Android/Windows: If you've got a few thousand dollars to shell out for a VR-ready PC and an Oculus Rift headset, you can play in virtual reality right now. If you don't, VRidge can let you play those same games on your phone inside a Google Cardboard set.
The app uses a server running on your Windows PC to launch games on your phone. VRidge is compatible with Oculus Rift games as well as support for Steam's VR standard, which is currently enabled in a few games like Job Simulator and Space Pirate Trainer. The developer warns that VRidge is still in beta, so if you plan to buy VR games just to play with this app, you're taking the risk on yourself. Also keep in mind that while some phones have super high-res displays, most probably can't match the quality level of an Oculus or comparable headset. This won't be a perfect experience, but it's a heck of a lot cheaper than the expensive setup you currently need for a full VR system.