Let's see, the worst chat up line...that's tough. Possibly the geeky engineer who came up to me at a dance and asked, "Is that your real hair?"

Or maybe the guy I ran into at a hotel at Worldcon, who tried to impress me by telling me that he it was his job to order 25 pizzas for the Klingon Party. Hey, not every Klingon can be entrusted with that kind of dough...