Really.
People have been speculating about this sort of thing for years, but one of the nice things about having a decent-sized orbital facility is that we can actually prototype them, and figure out if any are interesting enough to think about building inflatable stadia for them.
If the urban legends are correct, then zero gee sex is a team sport...
Space may make badminton somewhat enjoyable.
With some small, electric turbofans we could actually play Quidditch. Now that will be fun.