Atari
Atari 2600 (Jr. Model)

Coleco
Colecovision

Mattel
Intellivision II (boxed)

Nintendo
NES (model 1)
SNES (model 1)
GameCube (indigo)
GBC (atomic purple)
GBA (Glacier) was lost at the laundromat
GBA SP (Cobalt) was stolen with my purse
GBA SP (Pearl Pink)
Nintendo DS

Sega
Sega Master System (model 1, w/ built-in Hang-On game)

Sony
PlayStation 2 (PSTwo - slim form factor model)

*edit - Jan. 2006* I updated this list to reflect what I've added or gotten rid of since (this was 2 years ago, after all). I never did get a Dreamcast.