HALO 3 RACING
The original Halo was one of the first shooters to incorporate free-roaming vehicles and incorporate them really, really well. The feel of driving a Warthog is as memorable and beloved to fans as shooting a plasma rifle.
So naturally, racing is one of the most easily and entertainingly recreated sports in Halo 3. The vehicles are fast and the maps are huge - all you need to do is add some structure. Make a closed track with obstacles in Forge or create an open derby by arranging a few waypoints.
Mario Kart ain't got nothing on a Mongoose and Spartan Laser.
Racing on almost every map
Neck and neck on Narrows