Before engaging in a Top (insert number) list of hottest (insert gender), one must address this question: What is Hot?
Well, I had always been under the impression that like many modern usages, the conflation of "hot" with sexual attraction came from Shakespeare. The Online Etymology Dictionary states that it "dates back to 1500." For my intents and purposes, this is what I mean by it: "Hotness" is that state of being in which the sight or thought of an individual inspires sexual thoughts.
So by that rubric, although I find Captain Janeway and B'Elanna Torres to be lovely women with many admirable qualities, they don't make this list. I have to have experienced the emotional/intellectual state mentioned above in order to put them on a list like this.
And of course, any list like this is quite subjective. You can amend the criterion above, for the purposes of my list, to: "Hotness" is that state of being in which the sight or thought of an individual inspires Matthew's sexual thoughts. And given that this is the criterion for such a list, please excuse me if I dip into some saucier linguistic expression, here.
All right then. Without further ado...
Honorable mentions:
Here are characters who may have reached the threshold of inclusion if it were not for some mitigating circumstance.