I used to work at a Game Keeper, a board game store owned by Wizards of the Coast, and in the down time I would learn new card and board games to help me sell the games in the store. Fluxx and Chrononauts were two of my favorites, and I would regularly bring my own copies in to play with customers who were looking for something fun and new. Fluxx was perfect for an in-store demo, because you can always deal a new player in and bring them up to speed. I also highly recommend the Looney Labs game Nanofictionary, which is great for a creative group who loves making up stories. There are a lot of great games out there that people normally pass over, and with the slow demise of the American Board Game Store, I think we'll be stuck in a world where people only ever play Monopoly.