Get it for 360, there a bunch of better players there.
But if you want it to be mostly lag-free with less skilled people, then get it on PS3.
ok for one less skilled people? kid i would beat you 20-0, and i am pretty sure that ps3 has just as much "skilled" players if not more then xbox you fool. xbox just got a crap load of little 10 year olds, i had one once and hated it, xbox freezes constantly.
you will find the odd decent play in mw2 for xbox, this syndicate kid really must just be a pub star he see's a decent play and is like OMG ADDED. if you wana see skill got to ps3/queerbox GB/mw2/teamladders and you will see poeple with lots of skill. kid is just some BK random in a pub using an LMG thinking he's good. LMFAO to what u said about modders. on ps3 you will find maybe 1 modder in a year of playing but on xbox 1 million users get banned hmm?