If you had a 16ft x 18ft finished basement in your house. How would you utilize it?

The house we bought about two years ago has a wonderful 16’x18’ finished basement. It’s carpeted and painted and climate controlled. We just can’t seem to decide what to do with it. For a while it was a media room, but we got to where we never really went down there much. Now it is a guest bedroom although there is no restroom down there. I was just looking for some unique ideas about what to do with it. Also, we have two little children three and 6 years old.