So a forum I visit has the tournament of randomness, in which a bunch of nominated characters compete over bizarre activities. The current round had an unusual number of awesome matches, I thought. I grabbed 4 of my votes and explanations!
Bowser v Kefka Palazzo - Chess
Interesting match. For all his bravado in stealing princesses, Bowser is ultimately a very defensive player when the chips are down - he'll castle up and stick King (Koopa) behind elaborate defenses that would require precision movement and jumping to penetrate. Kefka, meanwhile, would ignore Leo's advice and throw away his pawns in a frontal assault - only really moving them at all because that's what's expected of him - before eventually micro-managing the Queen and moving it exclusively. As it happens, one micro'd piece is exactly Bowser's weakness, but that's not to say Bowser loses - if the game goes too long Kefka will get bored and either start making illegal moves like "my Queen blows up everything!" or tossing his own King off the side of the chess board to tumble to its doom on the floor. Which would be resigning. So... does the game go long enough? Good question, but modern Bowser seems to have severely clamped down on unauthorized warp zones and whistles, so thinking he can stall this out long enough for Kefka to go erratic. But it's close!
Dahlia Hawthorne v Yugi Moto - Cat Bathing
If she can charm butterflies, she can charm cats. (Or, failing that, even is a poor shmuck gets cat-shredded trying to do the bathing, that's not her problem!)
Terra Branford v Bender Bending Rodriguez - Stealth Match (aka The Metal Gear Challenge)
Sure, Vanish. For all that this doesn't work very well in avoiding enemy encounters in-game.
GLaDOS v Sarah Kerrigan - Burning Heretics
Psionic Storm isn't really fire, and Kerrigan doesn't exactly have any dragons among her Zerg minions. That said, Kerrigan can surely mind control a bunch of firebats and hellions to go do her dirty work for her. That said, it wouldn't matter if who could burn heretics better, for which the answer is obviously (and confirmed in-game) GlaDOS. That said, judging from the description, it's who can burn (N/2) + 1 heretics faster, where N is the pool of heretics. Kerrigan takes awhile to get going - faked distress signals, etc. to bring in her soon-to-be-infested friends - but burns pretty quickly after that. GlaDOS can only send so many people through the flaming obstacle course of doom at a time, though, can't have too many heretics in the same room together sharing ideas. So in short, if the pool of heretics is small, GlaDOS wins; if it's big, Kerrigan wins. As is, tiebreaking for "kills better" anyway.