A few of my favorites, from a list shared around the office entitled "Creative Comeback Lines For The Workplace"

1. Obviously you’re unable to assimilate my stimulating concepts into your blighted and simplistic world-view.
2. What am I? Flypaper for freaks!?!?
3. I’ll give you a nice, shiny quarter if you’ll go away.
4. How about never? Is never good for you?