I'm gonna go ahead and vote for the PS3 for a few reasons.
Granted the xbox i had was about 2-3 years old but the issues I have with it are as follows:
1) beware of the "red ring of death" or any red light on that console for that matter. if you dont know what it is, google it and read the horror stories. I'm sure they have addressed that issue with the newer models but the customer service is where they lost me as a customer.
2). I got a red light on my xbox and an error code that would come up rendering my system useless. I called customer service and they told me there was nothing I could do unless i paid them 150 dollars for their inhouse repair being that my unit was out of warranty. I asked to speak with a supervisor to which i was denied being connected to. I then sent them an email expressing my distaste for them and what had happened, to which they replied basically sorry. if you change your mind we will gladly fix it for 150 dollars. They also completely disregarded the fact that literally 1 day prior to the "melt down" i had just spent 150 dollars on the xbox Kinect (similar to wii) plus another 150 on games for the kinect (all of which are non-returnable). Unbeknownst to me, my mom bought another xbox on ebay for 65 dollars (she wanted this because the kinect was for her) which had a different red light error code and was an older unit than mine. She called them to see about warrantying it and voila, they did. So the customer service with them is sketchy at best
3) Lastly, you have to pay 60 bucks a year to play online vs free with PS3.
Sorry for the rant but there's my .00000000002 cents as Gregweld so eloquently puts it.
Good luck and have fun!