N64:
Rocket: Robot on Wheels. Sure, the game was easy, but it was fun. It had a neat little feel to it, like it was the kind of game that would have been popular in the 1950s, if they had video games in the 1950s. Which they didn't, which is a shame, since this game is just ridiculously obscure, when it deserves so much more respect. It was the first game to have a physics engine, but fuck, did they ever do an amazing job with it. The final level, though. The final level. Oh god, the final level was so stupidly hard.
GB/GBC:
Dragon Quest 3. Never got very far in it, on account of not caring enough, but it's one of the few turn based JRPGs that's, you know, hard. But, fuck, is it ever GRINDY.
GBA:
Kirby & The Amazing Mirror. What more needs to be said?
GC:
Tales of Symphonia. Not the best Tales game, but hell, it was fun. It was also one of two things; extremely grindy, or extremely hard. Take your pick.
Wii:
Position reserved for Tales of Graces having a US release, because I know that if it ever comes out here, I'm going to play and be screaming "BEST GAEM EVAH" for months. Sadly, I don't read Japanese, so I don't have a copy of it. Fucking Bamco of America.
PSP:
Persona 3 Portable. "Aaawwww, how cute, it thinks it's emo!.." In truth, it's just trippy.