I think this one depends on the context, but people tell me, surprisingly often, that they wish they had my hair. This wouldn't be too bad, except only women say it to me, and I'm a guy. A guy with a beard at that. One girl elaborated and said that she thought any girl would look great with MY hair. Maybe I'm just overthinkg this, but isn't that a backwards of saying I would look great as a girl? Because that's pretty creepy.
EDIT: I've remembered another one. After a friend of my had a brief but pretty offensive rant about how ugly ginger people are (I live in the UK), they turned to me and said "Don't worry, you're not that ginger anyway." Come to think of it, the ugly gingers stereotype only seems to apply to men, which might be why everyone seems to want to put my hair on a girl. I still don't feel any better though :/