Probably Drake of the 99 Dragons. It is actually rated as one of the worst games ever made, but I found the glitches to be rather entertaining. There has never been a game that has tried to do all the things that this game did. It's a REALLY hard game too, but once you figure out how to play it *I recommend a joystick controller* it's a really fun game. I honestly don't think anyone that reviewed the game, actually attempted to play through it all the way, or maybe people just don't like this sort of game. I had fun with it enough to play some levels again. If you want a game that abuses you, go for it. If you want a game that gives helpful tips and guidance, turn away.
Megaman ZX, have you tried it? (GBA title)