This app was mentioned in 3 comments, with an average of 2.67 upvotes
I showed my family on Thanksgiving and they loved it.
I recommend the turning forest. The 3D seems a lot better on things that were actually designed in 3D. Things don't look as "present" in YouTube 360 or street view or photo spheres.
The most popular app I showed was polyrunner. The kids really liked that one.
A fun video I recommend is this virtual eaten alive by birds. It always gets a reaction.
Also I definitely recommend casting your screen to a tv with a Chromecast so everyone can see what the person is seeing. It makes the experience way more social and less boring for other people.
I would absolutely recommend these games::
1) The Turning Forest - This was developed by the BBC and is a quality VR app.
https://play.google.com/store/apps/details?id=uk.co.bbc.turningforest
2) The Arcslinger - This is a shooter style game that is a cartoon western. The violence is not over the top.
https://play.google.com/store/apps/details?id=com.brbent.thearcslinger
3) Underworld Overlord - This is a tower defense style game that has been fun for me.
https://play.google.com/store/apps/details?id=com.otherside.underworldoverlord
4) Moatboat - This game is almost in the style of one of those godlike games.
https://play.google.com/store/apps/details?id=com.moatboat.moatboat
Lastly, if you are looking for reviews or videos on the current game selection before you purchase a game I would suggest looking at sites like :
http://www.daydreamdistrict.com/
The guy who runs the site or at least does the reviews for it seems to be pretty active here /u/daydreamdist