I've enjoyed the most time on my little old Nintendo 64. But since it died i had to start a new life with the Nintendo Gamecube, i really love the games on the GC specially when they released Spyro for Nintendo also. The Playstation is my least favorite of them all, i should never ever buy one though. Anyway i was lucky to found out about Rom Emulators, i can always enjoy the old games every day. I played to much with the Snes, N64 and GC... It was so fun, but unfortunatelly they died after some years.
Now i voted for the Nintendo Wii, i had such a great hope for it. I already own many great games and they will release very nice games soon. I love the controls and finally we got the bigger CD's back. Super Smash Bros Brawl is such a perfect game in my opinion, i waited like 3 years for it. I was happy they finally released it and now i am playing it with a lot of fun. I don't really care about graphics, it's not important to make a game great. I love the Zelda and Mario games over my hearth.
My second choise is the N64 though. however i have to play the games with a emulator, and they doesn't run very great. Well, some of them are crap.
I hope the Wii will release many more top games.