PC:
-can't really remember, but I'll say Chip's Challenge
SEGA Genesis:
-Sonic 1 or 2 (can't remember which I got first)
Game Gear:
-Sonic Triple Trouble
Game Boy Color:
-Pokemon Blue
SEGA Dreamcast:
-Sonic Adventure
Playstation 2:
-ATV Offroady Fury 2
Xbox:
-Halo: Combat Evolved
Xbox 360:
-Mass Effect
I expect to get an Xbox One early next year when Project Spark is finalized.