It's been another weird gaming week. Following last time's encounter with the harsh realities of import gaming (my newly purchased PC Engine could only display a black and white image), this week has seen the disappearance of my better half's Nintendo DS. She apparently placed it somewhere 'safe from burglars' before we went away on holiday a couple of months ago - somewhere so safe that even burglars couldn't find it even if they tried to torture its location out of us. During my search I managed to find a broken Nintendo Entertainment System under the bed, an original PlayStation that I'd forgotten I owned, plus a whole pile of old ZX Spectrum cassettes.

This week I also managed to get around to watching District 9, which as our very own Rupert de Paula has rightly pointed out, is both audacious and brilliant. I wouldn't exactly describe Sharlto Copely's character Wikus as lovable (he is a foetus aborting, racist fascist with a clipboard, after all), but at least he finally redeems himself in the final reel, and there's no denying the energy and commitment in Copely's performance.

District 9 has also given us one of the most memorable alien creatures for some time; director Blomkamp's Prawns are daringly depicted, and somehow evoke our sympathy despite their predilection for cat food and cow heads. As a tribute then, here are my top ten video game aliens...

Dobkerratops - R-Type

An obvious choice this, since the area one boss from Irem's shooting classic is one of the most iconic sprite designs in all eighties gaming. A huge, pestilent mass of eyeballs and curling tendrils, this creature burned itself into the consciousness of a whole generation of arcade dwellers. Area two's throbbing heart and curling snake were similarly iconic, and trickier to beat.

Invaders - Space Invaders

No list of iconic gaming aliens would be complete without these little terrors - only a dozen pixels across, these diminutive xenomorphs are iconic nonetheless: once played, few can forget their steadily increasing speed, or the heartbeat-like thump that accompanied their hypnotic movements.

Headcrabs - Half-life

A game full of memorable critters, the headcrabs make the list for sheer 'ugh, get it away!' ickiness. Though clearly modelled on Giger's facehugger designs for Alien, the initial encounter, where Gordon Freeman has little with which to defend himself other than a certain blunt instrument, has since taken on an iconic status all its own. And you know when an alien design has reached truly iconic status when it's been made into an adorable plush hat...

Bees - Galaga

Quite why Namco decided to populate their sequel to 1979's Galaxian with antagonistic bees, but that's precisely what they did with 1981's Galaga - and what a handful they proved to be. Taking the swooping drones of Galaxian and adding more intricate attack patterns, Galaga's insectoid invaders were arguably the most memorable aliens in early arcade gaming, and strangely cute to boot. Galaga 88 (released, funnily enough, in 1987) made them even more adorable, expanding their population to include bees that steadily expanded when shot until they finally burst, others that hatched out of eggs while still others left behind a handful of larvae once killed.

Grunts - Halo series

Possibly the most feeble opponents found in any first person shooter, Grunts represent Halo's cannon fodder. Visually unremarkable (they're sort of squat brown things with pointy backs), they're made eternally memorable thanks to their squeaky, panicked utterances at your approach - think of South Park's Cartman having a panic attack. Exclamations such as "I'll get you, you big giant freak," along with the occasional shriek of "bastard!" are, once heard, hard to shake.

Wretches - Gears Of War

Fast, short and stealthy, these critters (a sort of alien greyhound that could run along ceilings) were memorable for all the wrong reasons. While an initial encounter, trapped in a narrow hall beside a locked door - was a brilliantly tense introduction, their sole reason for existing thereafter seemed to be as a perpetual annoyance. Playing GOW on harder levels unleashed great swarms of the things, who bite at Phoenix's ankles until he collapses in a heap on the floor. Or maybe I'm just rubbish...

Ryan writes his gaming column every week at Den Of Geek. Last week's is here.