Multiplayer tower defense games for Xbox 360 with 2-player local/couch support
Plants Vs. Zombies
Players: 2 local, 0 online
Dungeon Defenders
Players: 4 local, 4 online
Toy Soldiers: Cold War
Players: 2 local, 2 online
South Park Let's Go Tower Defense Play!
Players: 4 local, 4 online