"She has a nice
personality" is what you say about the fat girl or the ugly girl because
you don't want to say anything mean. She can be a troll or coyote ugly but if she has any redeeming quality (such as big tits, nice clear skin, good teeth or decent lower legs) or you just
don't want to be rude in front of the person you're talking to, you say this.
1: "I'm gonna
hook you up with my girlfriend's
best friend."
2: "What does she look like?"
1: "Um... she has a nice
personality!"
2: "you mean she's not very good-looking?"
1: "um...true, but Ellen tells me that she pays her own way and gives great blowjobs"