First run ran was B1: In Search of the Unknown. In came in the Blue Box 1st Edition I got for Christmas. The first one I bought was B3: Palace of the Silver Princess, because a friend of mine purchased B2: Keep on the Borderland, which I got to be a player. Unfortunately, I never got the chance to run B3. The next one I would run would be U1: Sinister Secret of Saltmarsh, which I purchased a short while later. It was the first adventure that I think I finally got a handle on how to be a DM.