I found a great website by Dr. Katrin Becker, who has put together a fine collection of masters and doctoral theses on video games studies from 2000-present. So far, it has mostly theses from Canadian universities, but if you have a completed theses on digital games, I highly encourage you to submit it to her site. Her collection has been mentioned on a few blogs I subscribe to, so it might get you some attention.

You can use this template and page to submit your theses.