I had 5 connected and being used for a bit. Xbox, 360, Ps2, Ps3, and a Wii. Currently only have 4 though, xbox sitting in the closet.
I do still have my snes and 64 stashed away some where. I no longer own the 2600, jaguar, coleco, ps1, or the nes.
I guess the commodore 64 and that texas instruments thing we used to own don't count, since they are computers....more or less. No lo0nger owned anyway.
Eventually I'll get around to buying the ps4. The ps2 will probably be retired then though. And, the xbox 1 ever gets a game I wan't to play, then I'll get one of those too. If I retire anything to make room for it, would probably be the wii.
Doubt I'll ever own a wii u unless something changes.