Nothing unique here, but a li'l explaination:
MGS4, was the first I bought, and I loved it, but it's certainly not for everybody. If you weren't dieing to get it, you probably don't want it.
As far as I've seen, uncharted 2 makes the best use of the hardware for "ZOMG THIS GAME LOOKS SOOOOOO GOOD". Part of that is the more story-like aspects of the game, and crazy awesome locations allow you to really look around and drink it all in. It stands as a strong example of how much more you can get out of the ps3's processor when you custom tailor code to the ps3, instead of just switching the language around for a multi-platform release. There might be better examples of this around, but that's the best one I can think of.
Heavy Rain is quite a unique game. Probably want to look into that if you're into that sort of thing. I loved it, great story/acting etc. and I really enjoyed the whole feel of it. It's as absorbing as a good novel. It also looks perfect, but in less of a "looking across the peaks of Nepalese mountains", and more of a "yep...that's EXACTLY how an apartment looks in the rain" way.
Ratchet and Clank is simply fun. Their sense of humor is just right for me, I hope you're the same. There's jokes, innuendo's, and obscenely large ridiculous weapons that play the 1812 overture as the fill the screen with bullets, shotgun shot, and random missiles. Who doesn't enjoy that?
I also enjoyed inFamous a lot. Good fun.