Best compliment I've ever received is when I was told that although I am pretty with makeup on, I look just as pretty without it on.
It wasn't even in a "pro-natural, stop wearing makeup, you're beautiful just the way you are, you don't need to change to be pretty" way! It was a shy, sweet compliment that I've never gotten before and appreciated so much. It's one thing to be called beautiful but it's another thing to be called beautiful naturally as well.
