I played endless hours of "Don't Touch the Ground." It can be played anywhere and requires absolutely nothing. The point is to get from one point to another without touching the ground. It boosts creativity and gets kids out there and active.
It's a fun game to play in the backyard, a park, or on a camping trip. In recent times, Parkour has taken over an the urban version of the game. I even played it indoors on the furniture, much to my mother's dismay.