Already finished:
#1: Super Mario Land [Normal & Hard] (Game Boy)
#2: The Legend of Zelda: Link's Awakening [Perfect Ending] (Game Boy)
#3: The Bugs Bunny Crazy Castle (Game Boy)
#4: Mickey Mouse: Magic Wands (Game Boy)
#5: Super Smash Bros. (N64)
#6: Super Smash Bros. Brawl [Subspace Emissary finished, All characters and stages unlocked] (Wii)
#7: Kirby's Dream Land [Normal Mode] (Game Boy)
#8: Kirby's Adventure (NES)
#9: Gurumin: A Monstrous Adventure [Normal] (PSP)
#10: Wario Land: Super Mario Land 3 [All treasures, Perfect Ending] (Game Boy)
#11: Ratchet & Clank (PS2)
#12: WarioWare: Touched! (DS)
#13: Super Mario Advance 4: Super Mario Bros. 3 [No warp whistles used] (GBA)
#14: Crash Bandicoot 2: Cortex Strikes Back [Best ending. 100%] (PSX)
New to list:
#15: Guitar Hero 3: Legends of Rock [Medium] (PS2)
(Those last few songs where insane; I'm surprised my strum bar still works after that. Anyway, GH3 was decent, but I would have liked it more if they didn't have guitar duels (Maybe as a multiplayer mode, but not a required part of single-player). I liked Rock Band more)