This is a new list for best exclusives sinse the last one was screwed up and for newcomers nevermind the "2008" part in the title this is Best Exclusives PERIOD. (This is all from Metacritic)
PS3
1. LittleBigPlanet 95%
2. Metal Gear Solid 4: Guns of the Patriots 94%
3. Ratchet & Clank Future: Tools of Desctruction 89%
4. Resistance 2 89%
5. Uncharted: Drake's Fortune 88%
6. Wipeout HD 87%
7. Resistance: Fall of Man 86%
8. Valkyria Chronicles 86%
9. Super Stardust HD 85%
10. MotorStorm 84%
Total: 88.3%
Xbox 360
1. Gears of war 94%
2. Halo 3 94%
3. Gears of War 2 93%
4. Braid 93%
5. Mass Effect 91%
6. Geometry Wars: Retro Evoled 2 90%
7. Forza Motorsport 2 90%
8. Rez HD 89%
9. Fable II 89%
10. Project Gotham Racing 3 88%
Total: 91.1%
Wii
1. Super Mario Galaxy 97%
2. The Legend of Zelda: The Twilight Princess 95%
3. Super Smash Bros Brawl 94%
4. Maboshi: The Three Shaped Arcade 90%
5. Metroid Prime 3: Corruption 90%
6. Tetris Party 87%
7. Zack & Wiki: Quest for Barbaros Treasure 87%
8. Bomberman Blast 86%
9. Art Style: Orbient 85%
10. Super Paper Mario 85%
Total: 89.6%
It's pretty close overall, but Xbox 360 is number one for exclusives