The forest island of Rune is new home to what Toxic Menges recently told me is "the best racetrack in Second Life". I just gave it a quick whirl, and can confirm it's certainly a leading candidate in that category. You rez a free vehicle at the starting point (dirt bike, ATV, etc.), hop on, and plunge headlong into a beautifully realized race course, with glowing red arrows helpfully guiding you along the way, up steep slopes, along the water, beneath snowy mountain caps, and more.
Rune is the work of Maxwell Graf, who is still adding final touches to the racing elements: "I haven't even really had the opening yet," he tells me, "though people can already come and ride the track. I still have to do the damage systems with blood and so on, the interactive elements."
"So when the bears attack they'll actually kill you?" I ask him. (Yes, Maxwell has made Steven Colbert's nightmare come true: bears bolt out of the woods and try to maul you off your vehicle.)
"They will, yes, and the sharks, spikes, wasps, lava, rocks... for elimination rounds during the championship events we are working on weapons for the passenger, like teams of two, so you can have one drive, one attack [with] trash can lids and stick, chain, I think." (Curiously enough, that part reminds me a bit of Road Rash, the videogame franchise Cory Ondrejka was working on, before he became a Linden.)
A supremely talented content creator, Maxwell tells me all this manic inventiveness was made as a response to frustration over content theft and recent Linden policy changes. "You begin to question your options, your reasons," he tells me. "I needed to find something fun to do, both in building and that others could come and goof out on. I'd love to see it become popular, but even if it's not, I had a blast doing it, and I needed that."
I think you are likely to share Mr. Graf's fun (especially if you bring your friends): Direct SLurl teleport to RUNE at this link.