A few times, all recently with minor exceptions.
I've also been called hideous by total strangers before, so it makes me feel very confused to be honest. I never know how to respond, as it feels as though if I accept the compliment I'll look big-headed or silly because I always feel it's just said out of pity, or that I'm overly negative and distrustful if I question them over what they're saying.
The best thing, I think, is for me to politely say thank you and stop myself from making it awkward by biting my lip and refraining from calling them crazy or liars.
Who cares if someone thinks you're unattractive? I have been called ugly too. I don't care if you think I'm ugly. If someone says you're pretty accept the compliment. No, you don't look silly or big headed. You look like a confident young lady.