The ultimate slogan to be used when a female is absolutely positively ugly and there is only one way to describe her ugliness. This may be confused with fugly, however this reference trumps the fugly category.
Man, that chick is "uglier than a sack of assholes".
adj.
Uglier than the ugliest cute thing, therefore, not cute at all.
(Derived from the famous Pug "Oscar" who, despite being ugly, manages to be cute. He is therefore the ugliest something can be while still being cute.)
"That girl isn't hot, but she's not uglier than Oscar."
"That guy is extremely rich, but he's uglier than Oscar."