Most of them can be used with games on Steam, and other stuff, like seeing movies, watching youtube, etc ,etc. And if you go adventure mode, you can enable some dev tools and you can even program your own games.
I know this is true for the Oculus Quest at least, I own version 1, and now during next week, will buy version 2. That is a bit lighter, has more memory, and has more refresh rate and pixels. The remotes are a bit better too.
The other models, unless you buy second-hand, are going to be almost all of them more expensive. But warning... if you buy Oculus, be prepared to be monitored, abused, and forced to use Facebook. LOL