I’ve been using Whirligig for years now on the Oculus Rift, but it works just as well on the Vive—better, even, since you can use the built-in camera as a passthrough to see your keyboard. Whirligig is nothing fancy, just a side-by-side video player, a.k.a. one where you can watch 3D videos you download from the Internet.
Any type of 3D video. Wink.
The Vive launch is less focused on non-gaming entertainment, so there’s no official Valve Movies app or anything. Whirligig is a fairly cheap point of entry whether you just want a digital cinema screen or are digging into a world of 360-degree content. Plus there’s a gimmicky-but-kind-of-cool Drive-in Movie setting.
Note: Whirligig is absolutely not user-friendly, with some barely-functional menus (F8 for Explorer, Y to enable SBS video variants). Be prepared to put in some sweat and blood to get it configured the way you want. Or just wait. There are probably more video players coming down the pipe for those who are willing to sacrifice some power and flexibility for a friendlier environment.