Something that may also have appeal to the HN crowd - Destinations (on steam) has many great places to visit, but the one that got me was mars.
It's photogrammetry from the curiosity rover's cameras, with a minimal amount of artistic blank filling, and a good explanation as to how it was done, etc.
Me, I sat there on a rocky outcrop listening to the thin wind whisper by, grimacing up at the central peak of the crater in which the scene is set, wondering if one day I'll see these photons first-hand. I may have shed a tear or two.
I would caution against demoing Hover Junkers to first timers, especially without an explicit and careful discussion of nausea first. It is the only game anyone has listed thus far that has 'unnatural' movement, which for me at least, causes extremely unpleasant nausea that lasts multiple hours after removing the headset.
While maybe these issues can be slightly mitigated, the underlying problem is the same as getting seasick or getting sick while trying to read in the back of a car; I imagine the state-of-the-art solution is "Dramamine" ;P.
Funny you mention that...my current approach for games that make me nauseous that I can't fix with FOV settings has basically been ginger gum and lots of fresh air breaks.
I've noticed the list of go-to demos hasn't changed much in the past half year. As a Vive owner I'm kind of feeling let down by the lack of compelling new content.
Next up is Job Simulator. Lots of fun and attention to detail in there.
Then Tilt Brush, because it’s surprisingly fun, even for non-artists.
Earth VR probably goes into the list at this position right here :).
The Cubicle (https://steamcommunity.com/app/452490) has a nice twist to it, but is far less polished than the ones I previously listed.
If the person is into shooters and online gaming, definitely Hover Junkers.