technically Gran Turismo 5 isn't out.
GT5 Prologue is out, and its okay. its just really polished up demo of Gran Turismo 5. They don't currently have a release date for the FINAL version yet.
here is what I have for my PS3, and i'll give ratings on a 10 point scale, 1 bad- 10 great:
Grand Theft Auto 4 - 10/10 easily one of the best games ever
Spider-Man: Web of Shadows: 8.5/10 Awesome game if you're into Spider-Man (red suit/black suit controls are awesome)
Dead Space: 9/10 This game is EPIC. Some of it is scary as hell, too.
NFS: Undercover: 7.5-8/10 *I've only got about 25 minutes into the game, but so far, so good. Not my favorite NFS, but its not bad.
Skate 2: 9/10 Another absolutely awesome game. Superior to the first one. I've played the hell out of this one.
I'm looking into Silent Hill: Homecoming, Metal Gear Solid 4, and maybe that Smackdown vs. Raw 2009 somewhere down the line. Tax return is coming in soon, so i might pick up a few extra games.