Definitely Elite:Dangerous - though whether it will support CV1 by the time of its launch remains to be seen. It is glorious in VR, especially if you have a HOTAS setup to go with it. I think probably the best VR experience of all the things I've tried, including EVE Valkyrie (which you'll get with CV1 anyway).
Basically Elite is as close as I can think of to living in the Star Wars universe, in terms of the quality of the visuals, the frankly epic soundscape, the astonishing scale of it, and the way it all feels seamless as you travel around the countless star systems you can explore. It blew me away. I spent a good three hours on the first tutorial mission, simply cruising around the asteroid field with my jaw on the floor.
That's for Elite as a VR experience. As a game, well... after enough time you'll see it leaves quite a bit to be desired. It feels unfinished. Like there are all these awesome mechanics and gameplay elements but the play itself is quite shallow. It is probably best thought of as a very, very high quality spaceflight simulator.
To be honest that is a tough question to answer before the v 1.0 runtime is released. There are alot of devs that are waiting to recompile or in the process of recompiling their games/software for the final SDK and CV1 hardware abilities. So we're all looking into the unknown who will be the front runners for this.
All I can say is I'm looking forward to the CV1 launch versions of:
Elite Dangerous War Thunder Project Cars Dirt Rally Ark Survival Evolved (Though I doubt this will be for launch as it's still in Alpha)