One of the things you have to get when you go to a convention, is a convention T-Shirt. I managed to get shirts for every year I attended except the first convention. Here's breif rundown of the shirts I did managed to get.
The shirt from GaryCon II is the only one I have that has artwork prominently on the front and back. Basic black, a gamer cliche if there ever was one. I believe the one from GaryCon I was white. Overall it's your basic con shirt with the name of the convention, the date and a nice statement about what it's all about.
