I love co-op too and wish more games had it. I believe it's just Mando + TMNT that have it from Stern, but I think Houdini/Oktoberfest/HotWheels should have it by now (can't confirm this, hardly any of them on location near me) along with TNA + Alice Cooper, maybe some P3 games as well.
Can anyone add to that list? Hopefully I'm missing some games.