Killzone 2 deserves more sales than it's gotten so far.
It's annoying how many people I'll recommend the game to at my store, only to find them trading it in later, complaining that it's not enough like Call of Duty. It's as if Call of Duty is the only shooter that exists on ps3. People aren't willing to give others a chance, despite their quality.
Killzone 2 and Resistance: Fall of Man are the only non-Call of Duty shooters that have managed to pass 2 million on ps3, and the latter only managed such a feat becuase it was the only good launch title.
At least 360 owners seem more receptive to different types of shooters, with Halo, Gears of War, and Left4Dead - all uniquely different styles of shooter - seeing success on the platform in addition to Call of Duty.