Firstly let me say I own both and they are both awesome! My PS3 is getting more action recently as I have been caning through inFamous. But as the above guys mention, xboxlive is the crucial point.
If however you aren't interested in playing online or don't know tons of people with 360's already, then maybe consider the PS3. Blu-rays are cool, and i would go as far as to say it'll last u longer =D, allegedly the ps3 has not hit its peak yet graphically. Some sources claim 360 has but this remains to be seen.
Final point, I have been through eight 360 consoles in 2.5 years. I have heard that the newer models have eliminated some of the hardware issues. Currently am using an Arcade, and awaiting repair on an Elite.