@ Gilgamesh
R2's main story is single player optimised, like Bioshock and the bulk of other FPS shooters.
You could try Calling All Cars from the PSN, it's a fun game especially in 4 player mode. Probably there are more such games on the PSN, like Rag Doll Kung Fu. I only have 2 controllers myself, for off line 4 player fun I need to go next door to my sister, she has another 2 controllers.