My opinion: PC/MAC > WII > PS2 > PS3 > XBox > 360...
I'd say that it depends on the style of game. RTS, FPS, MMO those kinds of games (if you ask me) really belong on a PC, they just work better on it. But if you want to play a Platformer or an RPG (turn based RPG that is) or a sports game, those really belong on a console (although I still don't really understand playing sports games, the way I see it, if you want to play a sport then go out and do it...unless it's Hockey or Boxing or something that can't be done in a local park).
now that makes sense, playing sports games that are COMPLETELY unrealistic, those can be lots of fun, that's why I loved playing the tony hawk series or the SSX games.
Depends on the game. Sports games I prefere the 360. FPS, RPG's, and RTS's, I prefere the PC. I've yet to find a sports game that works out well on the PC in comparison to a console version.