I am going to go with a definitive no. The only time people even pretend to not want a game due to it being multiplatform is if the game was "stolen" from their console of choice. Admittedly there is a section of zealots that back any game exclusive to a platform, but they are an extreme minority. Given an equal level of marketing, making a game multi-platform will always result in increased overall sales.

You forgot to add Lost Odyssey, Tales of Vesperia (EU/USA), Dead Rising, Crackdown, Blue Dragon, Banjo-Kazooie: Nuts and Bolts, for example.

Feel free to reply with more of your own picks.

MW2 is like at 19 million copies,not 14-15..lol

I'm tempted to say Darksiders if it had been exclusive for the 360, for example. It wouldn't work on the PS3 due to God of War 3.

Battlefield bad company 1 for example. The lag was unbearable and after playing the game at a friends house i was put off. Sony games have dedicated servers resulting in less lag and slightly more sales.

It is true that games with dedicated servers for online multiplayer would have less lag but that's in no way related to the exclusivity of a game. On the other hand, it makes sense that multi-platform games would sell more (all consoles combined sales) than a single-platform game.

Resistance1, Resistance2, Killzone2, Socom, Uncharted2, MAG, Warhawk I haven't ever expierienced lag.

CoD4, CoDwaw, MW2, BFBC, BFBC2, Fifa09, Fifa10, PES09 i recieve far more lag when i play online

Its mostly to do with Sony implementing dedicated servers wheras, multiplatform games don't. Also certain games on the PS3 do have more lag than on the 360.

Is this based off an assumption of poorer quality of work or the ideals of crazed boycotting fans? There's too many unknowns to answer this - is this one development team coding around the lowest common denomintor or split teams maximising the quality (resolution/frame rates etc.) with less limitations?

Still if I had to give an answer I would say on a majority 'no', but I'll speculate and say that Killzone 2 would have suffered with such a big drawcard on graphics, which would have been compromised with a multiplatform release, not to mention the console bundling as well. Was MGS3 bundled with PS2's by the way?

Some games can sell more if they are exclusive but some not. For example i dont think Devil May Cry 4, Call of Duty 4 will sold more if it was exclusive. Most established franchise must go multiplat to sold more with few exception like MGS4 and Halo 3. Those games were treated as biggest exclusive for each console. Both got hyped and huge marketing from Sony/Microsoft.

Exclusive would sold more if it was new IP. For example I dont think Heavenly Sword, Uncharted DF, R&C: TOD can sold more if it was multiplat. It is because PS3 lack of great exclusive that times so they treat those games as must buy PS3 game. There is some exception for new IP like Lost Odyssey, Tales of Vesperia. Those two were exclusive to X360 which dont have as many as JRPG fan like PS3. Same for all FPS exclusive in PS3 like KZ2 and Resistance.

Of course. Most of the top sellers this generation are Nintendo exclusives.