JoeTheBro on 23 April 2013
Going to be unique here and say Infamous. It has about twice the hype as killzone and is doing something unique. On top of that it's open world, a spin off (this works good since the main series wasn't huge), amazing graphics, and seems to have a deep story. I'd bet my sig that it's the best selling launch title.
But going by the OP's weird rules I'll just say Santa Monica's new ip.
