A computer != a console. (in game console form) I think the best is Xbox 360 as it has a very wide range of games and still gets updated. Also, Kinect. A redditor did this:
I'm a PS3 owner myself but that's primarily because i've been playing playstation since the ps1. Shame about psn being screwed over at the moment, apparently some people are phishing on XBL now as well as the psn problems (obviously the psn problems are far more serious). But to answer your question a top spec gaming computer is far better than any console, normally the consoles catch up when they're brand new but the pc's soon over take them again.
I do believe that a decent computer is superior than any console. Otherwise the x-box is far better. The social playing is so much better with the ability to talk to any of your friends playing any game. The exclusives are also a lot better than those on the PS3. Just a shame a lot of those companies are now no longer exclusive.