While I cannot say anything to disagree with the annoying over privleged 12yearolds you will find that on either system. Even though the xbox live isnt free(It should be) It is by far superior to playstation network!
Another thing to consider is exclusives. PS3 has been coming out with a few lately that look pretty interesting(HeavyRain,MAG &GodofWar3) Xbox has some excellent exclusives as well (Gears,Halo Etc.)
I own all the current systems and my favorite is 360 but I'm not slamming the Ps3 I think it breaks down to one question. Are you a hardcore gamer? If you said yes then go with 360 if you are more of a casual gamer go with the PS3. Reguardless which you pick they are both excellent systems and you will be happy with your purchase.