Still Own:
Atari 2600
Sega CDX (Genesis and Sega CD that's the size of those newish PC CD cases that PC games come in now) (hooked up, but no TV in that room.)
Sega Dreamcast (hooked up, but no TV in that room.)
Sega Game Gear
Playstation 3
Gamecube (not hooked up)
In terms of Emulators: NES, SNES, Genesis, Sega CD (Fusion Emulator is awesome, I can play my Sega CD games directly off the computer!), and quite a few Arcade ROMs via MAME32.
Owned but not forgotten:
NES
Sega Genesis
Playstation
Playstation 2
I tend to only buy a new console when the previous model has outlived it's usefulness via breaking or is given away due to charitable causes. In the case of the PS1, the center spindle chipped and had a chunk flying around in the spin area. Eventually games just stopped loading and I donated it to the circular file. I replaced it with the PS2 because I could still use the games that the PS1 wouldn't load anymore. In the PS2s case, the tray's gears were starting to grind so I sold it (for free) and bought a PS3 because I could still play my old PS1 and PS2 games.
The Genesis was given to a friend who had a house fire.
My brother stole the NES when he went to college 7 years ago. He still has it.
I'm more of a computer gamer now-a-days, when better games come out for the consoles I'll get 'em. For now, I'm sticking to the great PS2 games I still have.