Joint Operations: Typhoon Rising
The MP isn't very active sometimes, but if you get a friend to play a mission with you against AI its fun as hell, I usually snipe the guy with stingers and stuff while someone else does strafing runs in ah AH-6. Cool thing about this is that you do have set objectives, but you can choose certain ways on how to do them. For example, this objective was simple, capture their bunker. The Armory has a variety of weapons and there were Helicopters, Boats, and APC's to help you.