Buddy and I recently finished Resident Evil 5, that was a blast but we are looking for more games like that. First person shooter kinda game with split screen and co-op. Anyone know any games of that sort?
Even if its online its not a problem we can get 2 copies.

Here are my list of good Co-Op PS3 games:

1. Marvel Vs. Capcom 3
2. Dynasty Warriors 6
3. Monster Madness: Grave Danger
4. Lost Planet 2
5. *New* Upcoming Ratchet and Clank: All for One
6. Mortal Kombat Vs DC Universe

Lego Star Wars the Complete Saga, lego Batman, Lego Indiana Jones 1 + 2 Lego Harry Potter

If you're not always looking for FPS goodness, there is also Lara Croft and the Guardian of Light. Old-school isometric shooter with some nice coop puzzle-solving. PSN only, rather cheap.

Uncharted 2 also has online coop in their "Objective" mode which is like small story chapters in settings from the main campaign. They only take 5-10 minutes to finish, though, and there are only three in total, so you kinda need to find other reasons to get that game as well.

I know 8 games for now.

1. Army of Two (CO-OP Mode for Campaign)
2. Call Of Duty: World At War (Online CO-OP for Campaign)
3. Resistance 2 (Online CO-OP but different campaign mode than World At War)
4. LittleBigPlanet (Big time CO-OP)
5. Lego Indiana Jones
6. Lego Batman
7. Mercenaries 2
8. Sonic Ultimate Genesis Collection (If you're into classic gaming)

By The Way, If you want to know about the upcoming releases, or PSN Titles. I can list them for you.