Oh, the funniest one was "Notorious B.I.G"... These two girls I used to do would refer to me that way when ever we were out together.
I had one back in high school that a group of girls gave me. "Banjo". I couldn't figure it out and they would walk by me in the hall and whisper "Banjo". Finally, at my 10 year high school reunion I asked one of the girls what it meant. She took a few moments to recall and then laughed. She told me that I was like a "Banjo", meaning I had real big balls and a long cock, hence Banjo.