At the Washington Center for the Performing Arts, they've changed their volunteering gifts over the years, but currently (well, in the beforetimes), if we ushered for 20+ hours in a season, we'd get a certificate for one free ticket plus one half-price ticket. They can be used independently, so you could just get the one free ticket now and a half-price ticket for a different show. After that, you'd get something (I now forget what) at 120+ hours...and that's it. There are people here who also have volunteered 400+ hours in a season, but there's nothing after the 120+ hours.