So just one game per console that I own? God that's hard
Arcade Cabinet (I use a JAMMA board): Gun.Smoke
NES: Kirby's Adventure
N64: Conkers Bad Fury Day (But DK64 is good)
PS1: Resident Evil 2
PS2: Shadow of the Colossus
Gamecube: Windwaker
Wii: Donkey Kong Country Returns
360: Mass Effect Series
PC: idk I have too many steam games

but probably WoW
Ones I've sold
GB: Pokemon Red
SNES: Super Gameboy (even though thats kinda cheating)