Valve has added an Oculus filter to their search function. So you can go to Steam's search page, then check the Oculus Rift filter to get all the games with official Oculus support. Note that there are games with partial/alpha support for the Oculus Rift that this search will not find.
This also works for finding HTC Vive games on Steam.
At time of writing, the Oculus Touch has not been released, so be sure to do research on games to confirm you can use a controller, mouse & keyboard, etc. to control them if they list support for motion controllers.