Not being a PS3 owner, I am highly aware of those games that I want that are "Playstation only". Are there also games that are exclusive to Xbox 360? Which titles might a Playstation 3 owner be dying to own?
Halo and Gears of War are the two that come to mind first. Talk about two great franchises and huge money makers for Xbox, Bungie and Epic. There are others, but those two are the biggies that I can think of.