Ok here is what you need to ask yourself. What games do I want to play? (console exclusive or cross platform) Which controller to I prefer? Do I want to pay for REALLY good online or get pretty good online for free? Do I want a blueray player? I could just tell you which I think is the better system, but people need to really decide what they want based on these questions. Because honestly both systems are fantastic and have their strengths and weaknesses.
If you really want a strict answer I have a PS3