It only takes one game to make a piece of hardware sing. Remember the Wii? I didn't really care about it until someone showed me Wii Bowling, and it all snapped into place. That might have happened for the Oculus Rift at the recent Exile Game Jam. A game called Disunion puts the player in a public execution. It's a virtual guillotine sim, where the player is led to the chopping block (turned over chairs), made to lie down with their head exposed, and then the blade drops. The effect is enhanced by lightly tapping on their neck when the blade connects. You might say Disunion is the Oculus Rift's...
... killer app.
[accepts your applause]
To be slightly more serious, these things break out when someone comes up with a neat way to package it up. Things need to be specifically made for it to say: look what you can make people experience with this. I love Team Fortress 2, but that fact that it had been ported over to the Rift told me nothing new about the devices capabilities. I can experience Team Fortress 2 on my monitor, but being in someone's head, looking around and seeing the blade falling towards me, that's the Rift's raison d'être right there. An imaginative experience that gives me a little bit of hope for the Rift's future. It's not really a killer app, but it's at least a demonstration that there's more to be interesting things happening with the new hardware than FPS ports.
This sent me down a wiki hole. I thought of the guillotine as a crude, historic device, but they were being used in France right up until 1977. The last public execution was in 1939, and was filmed.