I only owned hand-helds all my life, but I played with a few Nintendo emulators too. Does that still count anyway?
GameBoy: TETRIS!!... No, way too expectable
It's actually Pok?mon Red, just because it was my first pkmn ever.
GameboyColor: Pok?mon Crystal, for obvious reasons.
GameboyAdvance: my so loved GoldenSun!
GameboyAdvanceSP: ... I guess is still the same system as before, but I'll say Pok?mon Emerald.
NintendoDS: again, it would either be Pok?mon or GoldenSun.
Nintendo3DS: ugh, now that's the most difficult choice
Let's say FantasyLife (though Heroes of Ruin was also close).
N64: Zelda Majora's Mask!
GameCube: Zelda Twilight Princess
Wii: Zelda Sky-... no, let's choose something different. Like AC-City Folk?