My vote will have to go to the starter of this thread, which I doubt is a surprise to anyone.
I base it on pretty much three things, from the most superficial to the most important:
1) She actually is, on a physical level, really beautiful. Before we spoke, I always thought she looked nice in her pictures, but she looks even nicer in "real time." The first time I saw her on webcam, I noticed her great features, eyes, and smile, as well as her demeanour. I could barely look her in the eyes for a while, or I'd turn bright red, and for two weeks I couldn't eat because my stomach was full of butterflies. I lost 15 lbs.

I think that is a good sign she is pretty hot.
2) She is enjoyable to be around. She is funny (disturbingly quick-witted, too). She makes me laugh more than anyone else can, sometimes with jokes, sometimes with the videos and stuff she finds, and sometimes with her quirks. She is intelligent and can hold a good, thoughtful discussion on a lot of topics. She likes an awesome variety of music and movies. She has a lot of feminine qualities that I like, but she also has a tomboy edge that I find really attractive. All these things make her layered and unique, which adds hotness points for sure.
3) As time passed, the butterflies stopped being constant (though they come often enough still

), because I was getting to know her better as a person, too. She may not be as confident in herself as she should be, or even as confident as she seems on the outside, but she has a silent, unspoken strength about her. And at the end of the day, confidence can be broken, it can be faked, and it can be possessed by those who did nothing to deserve it. But inner strength is a sign of a good character, which one has to earn, and it can carry a person through times that sheer confidence can't. She is also very kind, thoughtful, and giving, almost to a fault. She truly cares about those she lets into her life, and wants and encourages the best in them. In everything she does, she gives all she has, not for recognition or ego, but because she wants to know she has done it right simply for its own sake. These are qualities I have valued in others, and strived to achieve in my own life, for as long as I can remember. These things are the most important to me, and they are the reasons I am happy to have her as a friend. People like her make this world a better place, and in my books, that is pretty damn hot.

god, what a long post.