Best single player yes. Best multiplayer would probably go to Killzone.
My list. Funny how they are all two's. I think TLOU might be the next best one.
One of the worst actually.
As for Sony's best.. Well.. They don't have that many games that support MP. most of the MP games are third party development teams and actually better games.
That said.. depends what your friends are playing as to how much fun you can get out of something usually.
Uncharted 3 is the best game for me based on the ability to play with people I know and like. From a gameplay standpoint I could certainly be playing a vastly superior game, there are 100's.
I haven't played a whole lot of different (Sony's) multiplayer games, but UC3 is best one I've played. See, I'm a 3PS guy and I suck hard in FPS games. The health in FPS is usually low so it comes down to who sees who first gets the kill.