The Classic: Couch co-op with my girlfriend.. but which game?

Hey Polies,

I've recently played Rayman Origins with my girlfriend, and it was a blast to play with someone, (especially if it was your love) and we've put so many hours to Left 4 Dead 2, Halo's, Double Dragon Neon. I'm thinking about buying Resident Evil 6.

So what can we play now? Together.

She loves platforming, zombies and fps', so am I. She doesn't like military shooters and Portal. We prefer split screen campaing co-op on fps'. And we have xbox 360.

I've run out of titles :( Need your help.

Thanks :)

*EDIT*
The help is here! Thanks! So far I'm into (reduced list):

- The Cave
- Lara Crof and The Guardian of Light
- Marvel Ultimate Alliance 2
- Gears of War
- ilomilo
- Donkey Kong Country Returns