Are Team Building Games Really Helpful?

I am always trying to figure out how to get my department to work as well together as possible. I think that a lot of the team building games and things seem pretty silly though, so I am wondering whether or not they are really helpful. I am assuming that some of these sorts of things must be, so mainly I am trying to figure out what activities might be the best in order to help me with the department I am managing. Right now it is hard to get them to help each other out, they are too concerned with their own deadlines and pet projects.