This was one I was always hoping the original Grudge Match site would do, but no (though they did do Pinky and the Brain vs. Dogbert). So I put it to you: If Pinky and The Brain from the cartoon of the same name were to fight each other, who would win?
Brain has the advantage of greater intelligence, and he's successfully landed punches on Pinky on numerous occasions. But he's totally unable to see the flaws in his plans; every episode has Pinky pointing out some kind of problem with Brain's plan ("Oh, wait, no, no..."). Pinky, on the other hand, usually succeeds at what he tries because he doesn't over-think and over-plan. So I'd have to give this to Pinky, who will simply drop something heavy on Brain after Brain's electro-magnetic Pinky-destroying gizmo backfires.