I quite liked GT5 even though it was really unfinished and quite a disappointment compared to the others.
I bought an old PS3 so I could play Battlefront 2 on it, but as for PS3 exclusive games, I'd say Ratchet & Clank.
There is no Battlefield 2 on PS3. It was released in 2005 for the PC and had one expansion pack, plus two booster packs (that later became free), and was patched until 1.5. PlayStation 3.... hmm... MotorStorm, Uncharted, Crash Commando, Burnout Paradise.
Anyways, I enjoy the Resistance series, the Ratchet and Clank series, Warhawk is still fun, but probably the best game I've played is MAG.
Ah... He posted Battlefield so I thought he was talking about that. My bad... Liking the Resistance there though