Sparc. It's a VR sport that plays like a cross between dodgeball and racquetball, with a visual style reminiscent of Tron.
Personally, I love it to death, and it has a real community of players, with tournaments.
It's also very aerobic; people have used it for weight-loss, and it's easy to see whycome. Unless my smart-watch lies to me, an hour of Sparc = about 1,100 calories.
So cool.
If you play, or begin, you can find me under this same username (it's the one I use everywhere).