Being a past PS3 fanboy I've come to terms that online Xbox blows us out of the water. it may not have as solid of a fighting game community on non-western games, but the service and lag is superior. Offline it's debatable, but I do fucking hate profile switching (like omfg is that the most retarded system eve conceived). Games wise they both have good things Uncharted and Gears of War are polarizing titles...but FPS's like COD or Battlefield...should be played on a PC in the first place, so whatever one does that better is null and void( it's a retard olympics analogy). I prefer the Ps3 pad...but when you get into 3rd party peripherals, PS3 has the Split Fish to make shooters viable and xBox has those sexy as shit Razor controllers.
If i could do it again knowing what I know now I would do xBox, simply because online play occurs more despite the HUGE annoyance it is with offline fighting games.