SNES. I remember watching my dad playing (and beating!) Super Mario World on it somewhere between the ages of three and five. Speaking of that game, now I want to play it D:
(really late edit: btw, I did play it first, too. :D I... don't know why I thought the watching was relevant, because I didn't play it until, like, 6 or 7. o_O I must've been tired.)