I have Both, I hardly touch my ps3. It's collecting dust. I enjoy Xbox for better connectivity with friends, such as party chats. WAY better online play. I don't mind paying an extra 40-60 a year, cause Xbox serves you with free game downloads, contests, gifts, a bunch of other crap. You are paying for XBL so you will get the best quality gaming experience. Also, if you're more competitive, go for Xbox. There's a reason why it's THE console that runs in MLG. People say ps3 has better graphics, and it is true by specs, but most games are made in 720p. The xbox runs 1080p and so does the ps3. Honestly there's basically no comparison, so it's really stupid to compare the graphics. I have both, and I bet most of the people here only own one console, so they might not know what they are talking about.
I say go for the Xbox, I think you will enjoy it the most.
Side note: I trust Xbox with my credit card purchases. I would never think of using my credit card for any psn purchases.
Another Side Note: The xbox has constant features added to it, now if I want to I can personalize my xbox from any smart phone. Stream any kind of media to my xbox and from my xbox, all from a tablet or phone, and even a laptop. And it's free. They added a lot of features but it's basically Xbox on the Go. This feature was recently added a few weeks ago.
Last Side Note: DLC and exclusive content gets to the Xbox first. Psn users always have to wait for their new map packs, and add-ons.
I blatantly prefer Xbox over Ps3. I only use my ps3 for some exclusives.