Here is my list of systems I have owned in the past (never to be forgotten):
Atari 2600
Coleco Vision
NES
Atari Jaguar
Nintendo Gameboy
Commodore 64 (I don't know if you'd count that as a system)
Sega Master System
Sega Genesis
TurboGraphix 16 (Bonk's Adventure!! woooooo)
Sega CD...