Nintendo 64. Okay, seriously...
I don't have any of them. I do have a DS Lite, which I like. My old computer is only suitable for old games, which I've played quite a bit. My new computer is finally fully functional after three months, so next week I plan to get a mouse for it, which would allow me to actually play games (touchpad is too tricky for that). I guess, like Rokapoke, I'm more of a computer gamer. I've probably been playing Diablo II more than is healthy.
From my very limited experience, I'd say PS3. The one I've played the most is XBox 360 because I played Oblivion on my brother's console. I think it was only the day before yesterday, I mentioned that I would probably buy Oblivion and play it on my computer and my brother noted that he'd actually gone through two XBox 360's and had just bought a PS3. He said that he didn't know anyone who had ever had a PS2 stop working. For that matter, neither of us could think of anyone who had had one of the old Playstations stop working either. I'm sure it's happened to someone with any of the three generations of Sony consoles, but it's uncommon enough that I don't remember any complaints about it, whereas the XBox and the XBox 360 have laughable track records in that regard.
The only game I can remember playing on Wii was the new Super Smash Bros. and I very much preferred the Gamecube version.
