Squilliam on 08 December 2009
Your girlfriend is a gamer, the best system for coop between the two is the Xbox 360 by far.
The Xbox 360 has Gears of War 1, 2 + Halo 3 + Halo ODST + Fable 2 (not as good coop but it has it) as some of the most notable exclusive coop games whereas the PS3 really doesn't have as many excellent split screen games, off the top of my head really its just Little Big Planet which comes to mind.
Also you can lose yourself for hours just trying out all the demos of the different games on Xbox Live. Furthermore there are some excellent games like Psychonaughts, Halo CE, The longest Journey, KOTOR (I think), Fable 1 etc in their games on demand.
Tease.
Essay Pro