PS3 is better overall, but Xbox has a better community because of it coming out first and being cheaper.
Xbox doesn't have many exclusives, (and when I say exclusives, I mean ONLY on Xbox 360, not that "console exclusive" stuff) and they still use DVDs.
I have yet to see a person that can list 5 good Xbox exclusives that are only on Xbox.
(Gears 1 is on PC, Mass Effect 1 and 2 are on PC, MW2 is multi-platform, etc.)