I started off with a Gear VR, and found the demo "Introduction to Virtual Reality" was quite good to show friends the potential, without getting into apps which you really need to spend time in to get to understand. It wasn't a perfect demo, as the resolution was lacking slightly but it was OK.
Now I have a Go, and I'm disappointed to find the equivalent app isn't available, and in the one I can find "Welcome to Virtual Reality" the graphics are very basic compared to what you can get in other Go apps.
What do you use to give a 5 minute demo to a friend? Has anyone found anything really impressive?