PC:Counter Strike and Dope Wars.
PS2:Grand Theft Auto III, FIFA
Dreamcast: Soul Caliber
N64: Goldeneye
Xbox: Halo
Arcade: Galaga or Galaxian.

Vidoegames happens to be my other way to waste time when I'm not on the internet, I have actually have over $1500 invested in my gaming habbit, and im not even going to imagine how much into computers.