I am biased of course, however I cannot wait to see out D20 Delving, and get people to experience something that is so cool, new and unique.
Probably Axis & Allies. When I was stationed overseas (which can bring long periods of boredom), I painted all the pieces like they were minis...
A few other favorites for me.
AXIS AND ALLIES:
Reason I like this game is that I was a massive RISK player, and when A&A came out it was like RISK on steroids. I prefer the more technical play of the game and like a game that solidly lands at 203 hours of play, and A&I delivers that.
DARK TOWER
Dark Tower is another one I really enjoyed and has a lot of nostalgia for me. Being the first "electronic" board game I ever had exposure to.