From the PlanetPlaystation.com feature article:
"Sony’s line of home consoles has always been known for having some strong exclusives titles. As a publisher and developer, Sony has managed to craft some highly memorable franchises. From God of War to Shadow of the Colossus, Jak and Daxter to infamous, Ratchet & Clank to Killzone, the PlayStation brand is home to some truly stellar exclusive games. And as far as the PlayStation 3, there are plenty of titles both available at retailers and through digital distribution that are worth playing again, and again, and again."