alt Hacker NewsWhirlyBall[1], which is kind of like pelota + basketball in bumper cars, seems like a pretty good bet. There are only a handful of courts left, but I've done a few offsites at the Seattle one, and it's good fun.
The bumper cars are truly weird - they draw power from the conductive floor of the court, and have a one-handed control system that makes you trigger forward/reverse by turning the steering wheel a full rotation...