The Big Bang Theory’s 25 Best Episodes

From Comic-Cons gone wrong to love affairs gone right, we look back at The Big Bang Theory's 25 most memorable episodes.

LOS ANGELES - APRIL 9: "The Love Spell Potential" -- When the girls'™ trip to Vegas falls through, the guys invite them to play Dungeons & Dragons, causing Sheldon and Amy'™s relationship to take an unexpected turn, on THE BIG BANG THEORY, Thursday, May 9 (8:00 - 8:31 PM, ET/PT) on the CBS Television Network. Pictured left to right: Johnny Galecki, Kaley Cuoco, Mayim Bialik, Jim Parsons, Melissa Rauch and Simon Helberg.
Photo: Monty Brinton | CBS via Getty Images

The Big Bang Theory has delivered a massive 279 episodes since it premiered back in 2007 (for those keeping score, Friends only managed 236), an impressive achievement to look back on. While the overall legacy of the show probably won’t be solidified for some time, it’s true right now that there are some excellent episodes that may have been forgotten or overlooked. Here’s our pick of the 25 best episodes of The Big Bang Theory, from the emotional to the hilarious and everything in between.

25. “The Bakersfield Expedition”

Season 6 Episode 13

Looking back at The Big Bang Theory’s episodes, “The Bakersfield Expedition” is still one of the series’ best. This season 6 episode takes place about halfway through the series’ run, and is a great reminder of what kept people coming back to this show for over a decade. While on their way to Bakersfield Comic-Con, the guys make an unscheduled stop at Vasquez Rocks, where Star Trek: The Original Series was filmed to take pictures in their Star Trek: The Next Generation cosplay. Unfortunately for them, Leonard’s car is stolen during their photo-op leaving them stranded in the desert. Meanwhile, Penny, Bernadette, and Amy decide to give comics a try and end up so engrossed that by the time Leonard and Sheldon get back home, the women are having a heated debate about Thor’s hammer Mjolnir. It’s such a shame that the women’s newfound love of comics isn’t really explored beyond this episode, because it’s so fun to see them become so passionate about something new to them.

24. “The Celebration Experimentation

Season 9 Episode 17

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A three-dimensional portrait of a character who’s so often become a caricature in later seasons, “The Celebration Experimentation” really digs into Sheldon’s issues with people, crowds and celebrations. It’s really a Sheldon special edition of This Is Your Life, with Amy planning a party and, despite reluctantly agreeing, Sheldon freaking out. It’s a sweet idea but, when Sheldon is confronted with genuine affection, all the recurring guest stars and even Adam West, he retreats to the bathroom. Penny talks him through it and, at the same time, reminds the audience why they love the show.

23. “The Intimacy Acceleration”

Season 8 Episode 16

You can tell a lot about a show from how it deals with big character deaths and, with The Big Bang Theory being the kind of light-hearted comedy it is, there was thankfully only one to tackle over the course of its run. That was the death of Howard’s mother, of course, and “The Intimacy Acceleration” follows on from the previous episode’s ending in which Howard gets the bad news. It’s a tactful look at the later, monotonous stage of grief wrapped in a sweet episode in which Sheldon and Penny test whether they’re able to fall in love using intimate questions. Spoiler: they’ve always loved each other.

22. “The Friendship Contraction”

Season 5 Episode 15

If I were ever in an actual emergency, I probably wouldn’t mind having a roommate like Sheldon who insists on being prepared for every possible scenario. Waking me up on a random weeknight for an unnecessary emergency preparedness drill, however, is another story. “The Friendship Contraction” begins with this very scenario driving a wedge between Sheldon and Leonard and forcing the latter to invoke section 209 of the roommate agreement that essentially deescalates their relationship from friends to acquaintances. Sheldon goes to increasingly hilarious lengths to try and win Leonard back in his own Sheldon-y way. Meanwhile, Howard is desperate to get a cool nickname from his astronaut coworkers only to be dubbed “Froot Loops.”

21. “The Work Song Nanocluster”

Season 2 Episode 18

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Many artists and creatives often have to take on side-hustles in order to make ends meet in our cruel and unforgiving capitalistic world, and Penny is no different. With her acting career still stalled, Penny decides to try her hand at starting her own business to help supplement her Cheesecake Factory income. Leonard helps her create a website for her hair clips affectionately named ‘Penny Blossoms’ that quickly gets her a large order from the East Rutherford, New Jersey Gay-Lesbian-Bisexual-Transgender Alliance. While this is great news for her business, Leonard accidentally included a one-day rush shipping option, meaning that Penny has to make a thousand Penny Blossoms in 24 hrs. This is a fun Penny-centric episode that also features a highly caffeinated Sheldon and catchy sea-shanties.

19 & 20. “The Spock Resonance” & “The Earworm Reverberation”

Season 9 Episodes 7 & 10

It may be cheating to put two episodes in one spot, but “The Spock Resonance” and “The Earworm Reverberation” form a spiritual two-parter that explore Sheldon’s final regression before he fully commits to Amy. They’re two of the most emotionally raw episodes of the show and the first is a lovely example of the writers really understanding the role of fandom in these characters’ lives. If in the end The Big Bang Theory’s overarching theme is the evolution of four sad, lonely nerds into four fulfilled men, then these episodes are that idea in its purest form. Also: Stephen Merchant.

18. “The Pancake Batter Anomaly”

Season 1 Episode 11

The origin of so many of the show’s constants, including Soft Kitty, “The Pancake Batter Anomaly is a first season gem that benefits from the freshness of the dynamics as well as the fact that Sheldon’s particular brand of neurotic selfishness was still more charming than annoying. The best gags come from the lengths Leonard, Howard and Raj are willing to go to avoid their friend when he’s sick (“code milky green”) after “The Great Ear Infection of ‘06,” instantly giving the world a lived-in history that’s hard to come by for a show that was less than three months old at the time.

17. “The Wedding Gift Wormhole”

Season 12 Episode 2

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“The Wedding Gift Wormhole” begins with Sheldon and Amy perplexed by a crystal gifted to them by Leonard and Penny. They insist that it’s the beginning of a complex scavenger hunt that leads to their real gift, but the truth of the crystal is even funnier. It turns out that the crystal has becoming a running gag amongst the friend group after it was gifted to Howard and Bernadette by, who then regifted it to Leonard and Penny before they passed it along. But as funny as this may be, this episode ends on a rare sad note for the series as we’re reminded that Raj is now the last one of the group to find love and complete the cycle of the crystal.

16. “The Convention Conundrum”

Season 7 Episode 14

Featuring not one, but two big Star Wars cameos, “The Convention Conundrum” follows Sheldon as he tries to create his own Convention after failing to obtain tickets to San Diego Comic-Con. Unlike all of Sheldon’s other heroes like Bill Nye and Leonard Nimoy who have restraining orders against him, James Earl Jones is surprisingly open to Sheldon’s proposal and the two end up spending the day together getting ice cream, karaoke, and ding-dong ditching Carrie Fisher’s house. While Sheldon is living out his nerdy dreams, Leonard, Howard, and Raj decide to try and buy scalped Comic-Con tickets before chickening out in the most dramatic way possible after realizing that they could be banned for life if caught.

15. “The Focus Attenuation”

Season 8 Episode 5

While the men’s desire to spend a weekend brainstorming new inventions is the catalyst for the events of this episode, their tinkering isn’t the best part of this episode (though their constant distraction even without their girlfriends is pretty funny). This episode is great because it lets us see just how far Penny has come since we first met her across the hall. While Amy and Bernadette are partying in Vegas, Penny has to stay behind in the hotel room to prepare for an important work assignment. It’s clear that she takes this job and this stage in her life seriously, and it’s a really good look for her.

14. “The 2003 Approximation”

Season 9 Episode 4

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Change is never easy, but for Sheldon it might as well be the end of the world. Not only is Sheldon still reeling from his breakup with Amy, but he also learns that Leonard has been living with Penny full-time ever since they got married. This causes Sheldon to regress out of fear and act like he’s living in 2003, before he ever met Leonard, Amy, or Penny. This episode deals with Sheldon’s fear of abandonment well, not just playing his distress for laughs. “The 2003 Approximation” isn’t entirely serious though as it also features the rise and fall of Raj and Howard’s filk (folk music about pop-culture) band. Their one and only song is about Thor fighting Indiana Jones, and it lowkey slaps.

13. “The Terminator Decoupling”

Season 2, Episode 17

Leonard, Howard, and Raj are originally annoyed with Sheldon’s insistence on taking an hours-long train to San Francisco for a conference, but are soon distracted by the appearance of Firefly and The Terminator: The Sarah Connor Chronicles actor Summer Glau. Howard and Raj spend their time competing for her attention while Leonard is forced to handle a Sheldon who unfortunately left a flash drive with an important academic paper on it at their apartment. Sheldon hopes to impress his hero Dr. George Smoot with his research and must rely on Penny to send the important file to him.

12. “The Robotic Manipulation”

Season 4 Episode 1

Our first real glimpse of Amy Farrah Fowler, following a cliffhanger ending that saw Howard and Raj’s little dating site experiment achieve more success than they ever could have imagined. Yes, Amy is a completely different character than she was a season later, and it’s a little jarring to look back on, but Penny’s chaperoning of her and Sheldon’s date makes this a classic episode nonetheless. That, and the sight of Howard shuffling into the ER with a robot hand attached to his penis.

11. “The Countdown Reflection”

Season 5 Episode 24

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Though there are a lot of sitcoms that experiment with their format on a weekly basis, The Big Bang Theory has been almost stubbornly traditional. That’s what makes “The Countdown Reflection” all the more satisfying, as it cuts between Howard’s trip into space and his impromptu wedding to Bernadette. The juxtaposition and pacing of the reveal are pitch perfect, and it’s all topped off with the touching final moments in which each member of the group hold onto each other as they watch their friend go on the trip of a lifetime.

10. “The Barbarian Sublimation”

Season 2 Episode 3

The episode that sparked a thousand memes, Penny’s sudden descent into MMORPG shows an entirely different side to the girl next door and goes a long way to humanizing her at the same time. Growing more and more frustrated by her lack of success as an actress, Penny finds comfort in the online game she finds Sheldon playing, and proceeds to take things too far. What nerd hasn’t given up on life for a week or two and instead chosen to focus on their avatar’s life instead? Even now, the girls don’t get to engage in the same nerdy activities as their boyfriends, so “The Barbarian Sublimation” still comes off as a novelty.

9. “The Hawking Excitation”

Season 5 Episode 11

Of all the celebrities Big Bang Theory managed to snag over the years, none were more impressive than Dr. Stephen Hawking. While his presence became more and more frequent as time went on, this first appearance is expertly teased right up until the closing moments and all the more powerful for it. Watching Howard torture Sheldon in exchange for access to his hero is as satisfying for the audience as it is for him, but the real emotional kicker is hearing that he was just doing it for fun and always intended to give Hawking Sheldon’s academic paper. Aww.

8. “The Justice League Recombination”

Season 4 Episode 11

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Mo’ Zack, mo’ laughs. When the group imply that Zack is stupid, thus upsetting Penny, they invite both of them to be part of their Justice League group costume for Stuart’s New Year’s Eve costume competition. The getups themselves provide their fair share of chuckles – it’s fun to see Aquaman jokes from a pre-Jason Momoa (“Aquaman sucks”) world and Sheldon’s love of The Flash is always fun – but it’s really Brian Thomas Smith’s performance as Zack that makes this a brilliant installment.

7. “The D&D Vortex”

Season 12 Episode 16

If I found out that one of my friends was involved with a Dungeons and Dragons campaign that featured Joe Manganiello, William Shatner, Kareem Abdul-Jabar, and Kevin Smith and didn’t tell me, I would probably be a little jealous too. Sheldon finds out that not only is his friend Wil Wheaton the leader of said group, but that Stuart of all people is also a member. Wil secretly invites Leonard to join too, but after he spills the beans to Penny, Bernadette, and Amy (who love Joe Manganiello), gets kicked out thinking that Leonard and the others only want to hang out for his celeb connections. Not only is this episode fun for D&D fans, but it also shows how far the group’s friendship with Wil Wheaton has come.

6. “The Staircase Implementation”

Season 3 Episode 22

Ever wondered how Leonard ended up living with Sheldon? Well this episode is going to tell you, and explain why both the elevator and Leonard’s spirit are so broken in the present day. It’s standard bad haircut and prescient comment fare for the most part, but there are some inspired touches that make it worthwhile. More than anything, it retroactively shows how far a lot of the characters have come, especially Sheldon, and watch out for a cameo appearance from a young Steven Yeun as Leonard’s predecessor.

5. “The Stockholm Syndrome”

Season 12 Episode 24

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Ending a decade-long series is never easy, but The Big Bang Theory’s series finale does a great job of sending off these beloved characters. Sheldon and Amy become Nobel Prize Award Winners for their work, inspiring the next generation of young scientists. Sheldon finally acknowledges how selfish he can be, and uses his speech to thank his friends and family for their support throughout his life and career. Penny and Leonard prepare to start a family while Howard and Bernadette struggle to leave their kids behind while making the trip to Sweden. The queen Sarah Michelle Gellar also makes an appearance in the episode as Raj’s plus one for the ceremony. “The Stockholm Syndrome” is a near perfect farewell and one of the best episodes of the series overall.

4. “The Bow Tie Asymmetry”

Season 11 Episode 24

While this isn’t the very best episode depicting a big event in Sheldon and Amy’s lives, it is the best wedding on the show and what should probably have been the series finale. Not just because the guest star bookings peaked with Mark Hamill, the sense of finality and celebration in “The Bow Tie Asymmetry” is palpable, and note perfect when it comes to combining the necessary emotional beats with the laughs. Leonard and Penny may have started as the main characters, but Sheldon and Amy replaced them long ago, so what better way to cap off a season than having Luke Skywalker officiate their wedding?

3. “The Adhesive Duck Deficiency”

Season 3 Episode 8

The pinnacle of Sheldon and Penny’s odd couple shenanigans, “The Adhesive Duck Deficiency” is the moment the show realised what it had in Jim Parsons and Kaley Cuoco, running with it ever since. When Penny slips in the bath and dislocates her shoulder, Sheldon must be her knight in shining armour and, after getting her dressed (“does that feel like an arm?”), take her to the emergency room. The chemistry between them is brilliant as ever and, with the rest of the guys otherwise located, it’s a hoot watching them try to navigate around the many hurdles presented by the situation.

2. “The Bath Item Gift Hypothesis”

Season 2 Episode 11

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The episode most cited as The Big Bang Theorys best (though it just missed out on the top spot here), “The Bath Item Hypothesis” is the show firing on all cylinders, using all of the tools in its toolbox, and crafting a genuinely great Christmas episode at a time when those are few and far between. The best single moment of the episode, and quite possibly of the series, is when Sheldon, having spent the preceding days fretting about how to reciprocate Penny’s hypothetical gift, receives a napkin signed by none other than Leonard Nimoy. Overcome, he gives her a gift basket in every size imaginable, stresses that it’s not enough, and then offers her a rare hug.

1. “The Opening Night Excitation”

Season 9 Episode 11

While “The Bath Item Gift Hypothesis” may be the funniest episode of The Big Bang Theory, “The Opening Night Excitation” is its most gratifying. After years of seeing Sheldon and Amy’s relationship reach each tiny baby step one at a time, it finally came time for them to lose their virginity to each other. It’s a situation that you just don’t see depicted on TV – two people well into adulthood coming together no earlier or later than the right moment – and the writing and direction treats both characters with the respect and genuine affection they’ve earned.

The whole affair is juxtaposed with Leonard, Howard and Raj seeing The Force Awakens and being almost as nervous as their friends back home, which compliments the emotions of one half of the episode with the intense reservations and ultimate euphoria that could be genuinely felt in screenings around the world. It’s a celebration of geek culture, of love between unlikely pairings, and of both things existing in people’s lives at the same time. It’s a perfect episode, and the show’s best.