Xbox is more social and entertainment based, in my opinion. Some of the options available on it exceed the ps3.
Now, I LOVE my music, I can't emphasize that enough, and when I found out I could listen to it through my xbox while playing a game, talking to friends, or doing nothing, I was dumbfounded. With the Ps3 though, you can only listen to music on the "dashboard," I only know the xbox terminology for home screen, and it stops while trying to do something like loading and viewing my trophies.
The Xbox chat system is phenomanal too. I can have a party of up to 8, correct me if I'm wrong, people who can be doing completely different things, and I can simultaneously be a part of a private chat and game chat, and switch between the 3 within seconds. As far as I know from my Ps3, I can only do that if I'm playing the same game with one of my friends...
It is true that Ps3 plays blu-ray discs, but is that much of an advantage, movie wise? I already have a decent collection of standard disc movies, and I have no drive to update all of my movies with blu-ray, even if the look nicer, it's not economical. Having blu-ray itself is of course an improvement, but only if you have blu-ray movies.
Now don't get me wrong here, I love my Ps3 and Xbox, and it's mostly a matter of what I want to play, and who I want to play with, which dictates my time on them.