I had the good fortune to attend the San Francisco HBO premiere of Game of Thrones, Season 3. It took place at the Palace of Fine Arts and HBO went over the top.
Entering the venue, HBO had hired a dozen or so of actors to entertain guests in dressed in full character. The theater was packed with fans ready to watch the show. Members of the cast were in attendance. The author of the Game of Thrones season and producers of the show made themselves available for a Q&A following the premiere (interviewed by Walt Mossberg and Kara Swisher). HBO even followed up the premiere with an open bar cocktail hour.
All in all, a pretty cool event.
The actual season premiere was great. My only complaint about the show? Episodes are never long enough. Given all of the characters and story lines, it almost feels like the story progresses in small chunks throughout the hour and it's always over too fast. I wish each episode was two hours long.
Hopefully the producers are taking note ;)