Interfaces

1. Pressing buttons of an elevator.
2. Steering wheel of your car.
3. Traffic lights while driving.
4. TV Remote for a TV.
5. Dials on a stove to cook.
6. Pressing buttons of a microwave.
7. Pushing down the lever of a toaster.
8. Crosswalk signals.
9. Radio dials or stereo buttons.
10. Buttons of an alarm clock.

If I had to give a specific example I would say the addition of hand controllers to the Vive. They are easy to use yet you can do a vast amount of things with them. Coming from an artist point of view, seeing artists able to paint in 3D space in a virtual reality setting is amazing. The Oculus started off using an xbox controller which limits what a player can do, but they are releasing hand controllers to compete.

A bad example is one that was great in theory but terrible in practice, the Kinect. Most likely because there weren't really any good games for it. All the Kinect does is track your form in 3D space and relay the information to the xbox. Microsoft could have made a great push into VR since they already had a good tracking camera for it.