Prospective PS3 buyer...

Guys Im looking at getting a PS3 today, but I need a couple of game suggestions before I do. First off, I wont be buying Madden 10 or MW 2 as I already have them on 360, So I am considering getting either Uncharted 2, Killzone 2 or Demon Souls. I am a big shooter fan and KZ2 would fit that bill, but I have concerns over its multiplayer community either having moved on to MW 2 or that the games are full of hackers/cheaters or that there simply arent that many people playing.

As far as UC2 goes, I did play the first one a bit as I am a former PS3 owner and I here it is a good game, but doesnt really do anything new for the genre. Demon Souls has me intrigued as I am also a fan of the action or action /rpg type games. Which do you recommend?

You can't go wrong with any of the games your list but if you can only get one, get Uncharted 2 IMO.

Get UC2 my favorite game this gen and the online is very fun also. DS I haven't played but I do have the collector's edition. KZ2 was a great game once you got use to the aiming in it and I never played MP component to it. Make sure to get the R&C games as they are a lot of fun. Resistance series is also fun if you like FPS especially onlin co-op.