Basically every one of the 17 games I own for my PS3 is a PS3 exlusive. PS3 has SO many good exclusive games!!! I don't think you've opened up enough to Sony's game library man! Have you tried any of these games?
1. Metal Gear Solid 4
2. Uncharted 2 (and Uncharted 1 for that matter...)
3. inFAMOUS
4. LittleBigPlanet
5. Ratchet and Clank Future: Tools of Destruction (and "A Crack in Time" releasing in a few days) - may look like a kid's game, but I had a lot of fun playing it. I'm 23 years old btw..
6. Killzone 2 (unparalleled fps graphics and excellent multiplayer)
7. Resistance 1 and 2 - Resistance 2 has best online I've ever played (their co-op mode)
8. MLB '08, '09, etc. "The Show"
9. Motorstorm 1 is a real intense offroad racing game, limited gameplay options though.
Seriously man, I think no matter who you are you gotta give Sony's exclusive games library some respect. Oh, and their upcoming exclusive games? Insane.
1. M.A.G. (as you mentioned)
2. God of War III
3. Gran Turismo 5
4. Heavy Rain (looks like will redefine gaming in several ways: gameplay, emotion, graphics)
5. Agent (PS3 exclusive from makers of grand theft auto series)
6. The Last Guardian (newest game from Fumito Ueda of Ico games)
7. Twisted Metal PS3
8. Quantum (Gears of War-like 3rd person shooter)
9. White Knight Chronicles (RPG)
There are more, but I just mentioned the biggest games. Check these games out if you haven't heard of them.