Prior to Mario and Sonic at the Olympic Games it was impossible to pit Nintendo's portly plumber against Sega's hasty hedgehog. Their rivalry predates this joint release by a good few decades, however. Our money's on the chap with spikes growing out of his backside. Thanks to TJ Pollock for the pic.
Who knew a floating yellow mouth and a bunch of colour-coded spooks could find so much to quarrel over? Our guess is that the ghosts are anti-capitalist activists who find Pacman's slavish devotion to acquisition disgusting.
Final Fantasy VII gave birth both to the modern console RPG and gaming's most protracted catfight. OK Cloud. So Sephiroth killed your girlfriend, but really - what else did you expect from a guy with waist-length grey hair extensions? And as for you Sephiroth - bringing about the apocalypse is no way to make friends.
Easily the most mysterious of the festering antagonisms listed here. Who the gosh-darned heck is the disdainful, suited, apparently omnipotent "G-Man", and why does he keep placing softly-spoken Half-Life posterboy Gordon Freeman in temporal stasis?
Natla is an old-time Egyptian goddess turned modern-day demoness. Lara Croft, of course, is the heroine of the Tomb Raider series. Both are rather hot, and it is our fervent, frequently expressed hope that at some stage they'll let bygones be bygones and get it on.
The titanic face-off at the heart of Metal Gear Solid is a question of chemistry, when you get right down to it. Solids and liquids can't coexist: the latter must, by empirical necessity, strive to dissolve the former. Oh yeah, and there's some stuff about them both being genetically engineered brothers and one trying to nuke the world in a giant robot.
Perhaps the original gaming grudge, comparable to that between God Almighty and Satan. The bricks tend to come off worst in a fight, but somehow they're always back for more.
At the end of the day, you don't get more personal than a chainsaw. The sight of poor floppy-haired Leon Kennedy getting the DIY treatment - sadistically early on in the game, to boot - is something few Resident Evil 4 players care to relive. We still see red every time we walk past a branch of Home Base.
The alternately bestial and human Ganon is very much Noel Gallagher to Link's Damon Albarn. We're not sure what they (or for that matter the Legend of Zelda series) would do without each other, really. Much of the dislike centres on frequent kidnap victim Princess Zelda.
Zombies and Nazis often come together as villains - it's common, for instance, for the Nazis to create zombies in their secret weapons labs over the course of a game - but as joint top candidates for Most Ubiquitous Bad Guys Ever they're actually in fierce competition. Go undead!