Why do people give Resistance so much credit? It's only popular because there was nothing else available at the time. I admit, it's a decent launch title but other than that it's not that good of a game.
The basic premise it lame, the art style is boring, the game is easily broken (start a level and just run through it and see what happens), and the gameplay is completely uninspired. I could get the same exact experience by playing almost any other FPS.
As for on topic, I would say Rayman Raving Rabbids was a great launch title along with Excite Truck. Also, was Dead Rising a launch title? I know Kameo was and it was pretty good.