I've got too many to list, and, quite honestly, it doesn't matter, because I have Xavix + Jackie Chan's J-Mat.
Here's what I don't have:
Jaguar (I'll be getting one eventually), CD-i (yeah, one of these days I'll get one), game.com, Virtual Boy, PS1 (traded up for a PS2), Nomad (I used to have it), Vectrex (crap, yet another thing I need), ngage, gizmodo, PSP, DS, Wii, ps3, xbox360, pc-fx...