Personality, without question. I read this and had an answer in my head, but I just lost it when I wrote that first sentence. Umm...sorry.
I actually despise people who would be considered "hot", for the most part. They're so full of themselves and have awful personalities. What's worse, are those people who think their "hot". They act like Paris Hilton, but aren't attractive at all (kind of like Paris Hilton, Lol) and that somehow in a social aspect raises their "hotness". They have the worst personalities of all.
Things are backwards for me. Someone could look absolutely gorgeous, but if their personality is dreadful that's what I'd end up seeing. I end up picking up or sensing that personality in everything they do, their mannerisms. A trait that, for me, overrides any physical beauty.