What’s an insult that you will never forget?

Back when I was taking driver's ed, my instructor got me real good. He was just a sarcastic old guy, and we all just took it in stride. Part of his charm, as it were. One day, I was driving with him, and I was unsure whether to drive around a pothole or stay within the lines. I chose the latter, and the pothole was deeper than I anticipated. His response? "It takes a hell of a driver to hit the only pothole in the whole road."