MTB Freeride is a game I've had on my radar for more than a year. You might not think a biking simulator would be fun, but boy would you be wrong. Just give it a try and you'll find yourself leaning left and right and ducking and consistently cursing but never feeling frustrated. The developer just recently updated his build which now sports Oculus Rift support as well as other bells and whistles.
*Foul language warning for the video. I simply cannot play this game without swearing and I wouldn't have it any other way.
Try out the current build for free HERE.