It doesn't take much to ruin the integrity of a beautifully packaged DVD edition that collects a franchise's output into one fetishistic and shiny bundle. In the case of Bond films, all it takes is another Bond film (GoldenEye used to be on Bond's nose in the segmented side photo, but is now somewhere near his right ear). But nothing ruins that sense of completeness more than the single abberation, the unique mistake, the one that got away...

5: X-Men 3
Wherein a promising first film and an outstanding sequel were decimated - much like the majority of the cast - by a change of director and vision as Bryan Singer unwisely left the franchise in Brett Ratner's incapable hands while he went off to rape my memories of the Superman movies. Ratner hated Cyclops even more than Singer (who sidelined the character in his own two X-Men films) and gives him the least effective death scene ever, and the excellent idea of examining the moral quandaries of a 'cure' for mutation is thrown away in pyrotechnics and character-decimating carnage, as if every other X-Men character was just side-salad on the Wolverine steak.

4: Halloween 3: Season Of The Witch
Tommy Lee Wallace's tale of kid-murdering Halloween-masks is far from the worst of the Halloween movies; the car-crunching scene is effective and Quatermass writer Nigel Kneale is adept at this kind of one-off, bleak tale. Trouble is that SotW was intended as the first of a series of anthological tales for October release, leaving Michael Myers behind for good. The idea didn't take, and pretty soon the Shatner-faced looney was at it again. . Not only is this not a proper Halloween movie, it's not even a slasher movie.

3: Rocky 5
Stallone recently made Rocky Balboa as an apology to the public for this flaccid and flabby ending to a patchy but always exciting franchise. Here a brain-damaged Balboa has to fight his own ambitious protégé to the turgid backdrop of family problems. The fact that the crucial fight takes place in the street and not in the boxing ring is only one of several departures from the successful Rocky formula that fans and critics alike loathed. In conversation with Jonathan Ross, Stallone was asked to rate all the Rocky films and gave this one a fat zero. The kind of movie you dream up in a hungover moment of Jerry McGuire-like repentance; normally a croissant is enough to raise your blood sugar and kill the idea, but something went wrong here.

2: Exorcist II: The Heretic
The usually-excellent John Boorman is foolishly left by the producers to project his ongoing obsession with ecology onto the sequel to the most successful horror movie of all time. Richard Burton plays the priest wondering if Regan MacNeill (the now-mature Linda Blair) is quite over her scrap with Beelzebub, and is so drunk that he can barely stand. Half an hour in, you can't blame him. There's a (then) trendy obsession with ESP and lots of people in labs boring you senseless, and only one particularly dangerous bit of skyscraper sleepwalking is - ironically - likely to wake you up. Original author William Peter Blatty made an excellent sequel 15 years later, and even the Schrader/Harlin prequels provide more entertainment than this. Sheer hell.

1: Godfather III
This is not what I wanted!, cries Michael Corleone, who's been trying to give up the old crime lately; we can only echo his sentiments regarding Coppola's 1990 closure of the already-closed Godfather saga. There's far more wrong with this than the carpentry of Sophia Coppola (though that certainly doesn't help). The harking-back to the original films is an embarrassing bit of badge-waving that actually undermines what little authority the unlikely plot can muster. Having watched the Faust-like Corleone being tempted down to hell in the 70s Godfather films, we're forced to hear him say 'And another thing'. Further, Corleone's demise in the Vatican city must rate as the limpest death-scene in cinema history. Worst of all, as I've lamented before, if Coppola ever does release another chronological re-edit of the Corleone clan, this weak afterthought is unlikely to be excluded.

Near misses:
Police Academy (where, according to Simon, the first film ruins the box-set by being vaguely watchable).
Harry Callahan movies (The Dead Pool isn't any worse than The Enforcer).
Monty Python's Meaning Of Life (The sketch-collection And Now For Something Completely Different confuses the issue).
Tremors 4 (close, but 3 was no masterpiece).
Superman 4 (see Tremors 4).