I personally use an Oculus DK1 (it was the only thing available at the time) and play around with three.js + WebVR. You'd be surprised the fun you can have wit

I personally use an Oculus DK1 (it was the only thing available at the time) and play around with three.js + WebVR. You'd be surprised the fun you can have with WebGL. I can't show it off just yet unfortunately, but I made this web player for 360 photos and videos that has a VR mode. It came out better than expected. Thinking about moving to Unreal next, not necessarily because it can do something that WebGL can't, but because I'm simply interested in that route. While I'm sure Unity is a fine tool, I've had bad luck with them. I was interested in developing a mobile VR video player for 360 video, unfortunately Unity can't exactly map a video texture onto a 3D sphere, which is pretty much the standard way of making a 360 VR video. You can try taking the individual frames and mapping them onto the sphere as fast as possible, but the frame rate was a poor ~20fps, which I wasn't impressed by. It might be different for video, but last I recalled you should shoot for at least 60fps for VR experiences if you want to avoid the whole motion sickness issue. I've also played around a bit with Google Cardboard, and I have to admit, it's alright, but at the end of the day it's still a cardboard shell for your phone with special lenses, so if you really want to play around with VR an Oculus DK1 or DK2 isn't that bad. The Samsung Gear VR is a fine choice too, but only if you already have a Samsung smartphone, otherwise I'd still just recommend you go for the Oculus. So, those are my thoughts.