Atari 2600 - late 80s(?) don't really remember exactly when, my dad showed me his old Atari when I was a todler, so I hadn't quite developed long term memories yet :P
NES - 1991
Gameboy - 1992
SNES - 1993
N64 - 1996
Gameboy Color - late 90's
GBA - 2001
Gamecube - 2001
Dreamcast - 2004 (or whenever Sega dropped the price to $99, when they offically turned to desperation mode)
Xbox 360 - 2005
DS - 2005
Wii - 2006
Xbox 360 Slim - 2009 (does that count? :P)