Anagnos: That was a tough question to think of an answer to because I'm a pretty honest person for the most part. Even on the infrequent occasions when I do lie about something, it tends to either be a white lie so as to avoid hurting someone's feelings, and/or is a fairly insignificant issue anyway. Although that said, I can remember one time when I was a kid, I was over at a friend's house and he had all these impressive Lego structures built. When no-one was looking, I wrecked some of the structures... and then blamed it on my friend's little brother.
I still don't know if that's my "biggest" lie necessarily. I feel like there's probably an even better story buried in my memories somewhere, but that's what springs to mind right now.
ImpracticalDino: Thankfully not.