Oh wait. I just thought of one.
One in my Signature. (though i need to update it.)
Naruto: Clash of Ninja Revolution has a 2 on 2 battle system. There is a scenario mode though, so that may not count. All the other modes do have 2 player co-op versions. You just have to unlock them.
Man do i feel stupid... considering i must of played my way through that with my girlfriend 10+ Times.
Mario Strikers Charged also has same screen Coop. On just about everything i believe. Ah except minor challenges. Don't know if that counts.