I'll be honest with you, I wouldn't purchase a new console now.
The system cycle is starting to end (new Nintendo console out next year and both new Xbox and Play-station will be revealed next year). If you buy a new PS3/Xbox now, then next year you very well might be replacing (but there's also a good chance they won't officially come out until 2013, but they will definitely be revealed in 2012).
If I had no console, I'd be buying myself a gaming PC. PC plays 90% of games that come out on console, as well as their own exclusives. They produce much better graphics (higher res texture/draw distance/resolution/faster load times), the controls are also more free flowing than a controller. Keep in mind, current consoles are using hardware from 5 years ago. Any mid-level PC looks better than console games. It's more expensive, but is wroth it if you have the money.
With all that said, if you don't want to spend the money ($800-1000) and just want a console to sit on the couch and play once in a while, I suggest the PS3.
PS3 has a lot of great exclusives (look at Kry's list) where as the 360 Basically just has Halo and Gears at this point, as Mass Effect is now a PS3 game as well. PS3 is also a blu-ray player, so that's pretty cool. Also, the online is free. You don't have to pay to play games online with friends/anyone else.
The 360 is pretty cool as well, but it doesn't really do anything the PS3 can't do, and the PS3 can do somethings that the 360 can't, and has better/more exclusive game titles.