If you go with a computer-connected one you'll need a pretty good PC to run it. But the big plus with something like the Oculus is that if cost isn't a big problem you can keep up with all the technological advancements. And there's more games for it, too.
I have the Playstation VR, which every now and again will go on sale at GameStop. And probably getting cheaper with their VR2 pre-orders just starting to be offered. Playstation's VR1 can be run on a PS4 but the VR2 will need a PS5. If you have no console at home already, the Oculus may be your best bet.
Plus the Playstation VR, at least until v.2 releases, doesn't have joysticks, and so moving around in a Playstation VR game is always pretty awkward.
And I'll definitely say that putting a VR on an older relative who's never used one before, and then having them do a roller coaster or a scary game.....well that's just such a blast to watch as they scream or try to keep their balance. Last time I did it with my family there was a lot of cry-laughing.