My brother just got a PS3 and while its UI and the console itself look like utter (pretentious) garbage, it has some really nice titles available. Some also available for the XBOX 360 but some, like Uncharted, are exclusive.
I know I'll come off as a "Nintendo fanboy," but what games? As far as I could see, the only PS3 titles that looked any good are Ratchet and Clank and Uncharted. As far as I've seen the 360 has a far better selection of games.
I finished Uncharted during my Christmas break. The only way to describe it was 'incredible'. They did an amazing job with not just the graphics, but the atmosphere and especially the story. I enjoyed it so much that I took the time to watch the bonus videos, such as the making of the game. That is pretty much unheard of for me to do (when one of my friends heard that, she went out and got Uncharted that day).
I'm currently playing Rachet and Clank: TOD. Its the first Rachet and Clank game I've played, so the humor has impressed me so far. The graphics are nice also.
I do agree the XMB sucks. Even though I've had the system since Aug, I didn't even realize it had a 'friends' setup until one of my friends tolk me to add her as a friend so we could play Rock Band together. Overall, it just seems a lot less intuitive than the 360 setup.
One observation that I did make a couple days ago was that our (as in own) PS3 library is now roughly the same size as our 360 library. My roommate pointed out that a few 360 games were lent out, so the 360 still holds an advantage. My Gamecube and Wii libraries dwarf them both, though