Go for PS3, the point of buying a console is actually for their exclusives games.
You already have a pc, why bother Xbox for many of the games are already available on PC. (Except for a few, Eg. Halo)
PS3 can support most TV with HDMI.
PS3 is more reliable than Xbox360 in my opinion.
PS3 has many great exclusives, God of War, Uncharted series, Heavy Rain. Killzone series
You can find many used games with price range around 40-60.

PS. I own all of them, WII PS3 XBOX360, and I have a gaming spec PC.