If you're talking about split screen offline campaigns? I agree PS3 is lacking those. Although there are plenty of exclusive offline multiplayer games.
LittleBigPlanet
Motorstorm 2
Modnation Racers
Wipeout HD
Super Stardust HD
Resistance
Warhawk (though you do have to be signed in, you can still play local 4 player split screen)
soon to have: Gran Turismo 5 and Twisted Metal
You could argue that the 360 doesn't have as many good single player campaigns as PS3 games especially compared to Uncharted 2, GOW 3, and MGS4. Though I know what everyone means; the split screen campaign is really fun.








