The best advice I can give you before jumping into VR is to consider your hardware and intended uses first. If you intend to get something like to Google Daydream, then make sure you have a phone compatible with it. Sure, there are ways to force the app and setup on a phone not designed to be compatible, but you will suffer due to resolution and latency issues.
As for full on headsets (those that use computers to run), make sure you have enough graphics and processing power to handle the full resolution and framerate. If your system can’t handle the requirements, then VR will become a very uncomfortable experience.
If you haven’t tried VR gaming before, it’s a lot more fun than you might think. Realize though that having a screen pressed up against your eyes has been the nightmare of parents for decades now, ever since video game consoles came out. Intense lights and shifting motion in VR causes ‘simulation sickness’ in a lot of people. If you have problems with motion sickness, then you will likely notice the same symptoms. Personally, I get a mild headache after about an hour of VR, but these symptoms get delayed or removed entirely the more familiar you are with the experience.
For hardware choices:
If you want to try a phone-based headset, first order a Google Cardboard and see how well your phone works with its resolution. With the lenses in place, a lot of normally high-resolution screens have the ‘screen door effect’ where you can see the grid lines between pixels on the display. Some phones have more problems with this than others, which is why Google only has a small list of Daydream-ready phones that have the response time, sensors, and resolution to handle it without any problems.
For full headsets, it depends largely on your application. If you only intend to use it for videos and the like, then look around for a high-resolution system like the ones Pimax makes (google 4K VR Headset and check out some reviews). These systems will do great for entertainment, but they don’t have any game-ready hand controllers and most computers can’t run 360 degree environments in 4K anyway.
If you want to try it out for gaming, your best bets are the HTC Vive and Oculus Rift. The Vive has better room-scale tracking and easier setup (for now), but I honestly can’t think of anything beating the touch controls on the Oculus. Even with the new Mixed Reality headsets coming from Microsoft and partners, gaming in my experience comes down to how the game feels. Touch controls on the Oculus give really nice tactile feedback that does wonders to increase immersion. Having digital hands that react to your finger movements makes you feel like you are much more a part of the game.
A side note about tracking with the Microsoft systems: Since the tracking cameras are housed in the headset, your controllers are only truly tracked when in view of the cameras. Otherwise it has to go on accelerometer data to guess where they are. This should work fine for most cases, but action-based games will have problems with your arms jumping around you until the system is perfected.