Off the list, I've owned them all with exception to the Neo Geo. Unless you count MVS, but it's not a "console" per say.
Here is a list of currently owned that I can remember, in no particular order (number I own if more than one; +means I forget how many, but at least):
Atari 2600 (3)
Atari 5200
Atari Jaguar
Magnavox Odyssey 2
Intellivision
Colecovision
NES (9+, 1 is top loader)
SNES (5+, 1 is mini)
Virtual Boy (2)
N64 (5+)
Game Cube (5)
Wii
Game Boy (6+)
Game Boy Pocket (3)
Game Boy Color (6+)
Game Boy Advance (4)
Game Boy Advance SP (4)
Game Boy Micro (2)
DS Lite
DSi
3DS
Sega Master System
Sega Genesis(3+)
-32X
-CD
Sega Saturn(2)
Sega Dreamcast(2, one black one white)
Sega Game Gear
Sega Nomad
Xbox
Xbox 360
Playstation (6+)
Playstation 2 (3, 1 older, 1 slim, 1 Japanese slim)
Playstation 3
PSP 3000
Tiger R-Zone
Game.Com (2)
Neo Geo Pocket Color
Wonderswan
Wonderswan Color