Voted Jazdia.
Lookswise, Kira improved over the whole series. Season 1 didn't do her any favors (the hairdos). She's too outspoken and hotheaded for my liking. Jadzia across most of the series (pre-Season 5) was more to my liking. She's intelligent, beautiful, mysterious. Yes, she did have an unattainable air, though interestingly, based on the series, she was 'unattainable' until she turned into a Curzon Dax soriority girl and hooked up with Worf but she wasn't unapproachable. She was highly accomplished, very wise, yet didn't come off as elitist. 4 good seasons and 2 slightly to bad seasons still put her on top. Ezri Dax was just about the opposite of attractive in her classic personality (short, extremely short hair, awkward, very nervous) though I can see people going more for her later on or in her Mirror version.
As for the others. Leeta was certainly more attractive in specific areas than the others and she had a very upbeat personality. She was stronger-willed than her personality might lead people on to believe, but I felt she was a very common type of girl/lady, one I'm usually 'meh' about. Tora Ziyal I didn't vote for. I felt one of the actresses' interpretations of Ziyal was very charming and endearing, albeit naieve and couldn't remember which of the three. I do remember at least 2 of the 3 being good and having strong points where the other had weak/neutral points. I think it was the 3rd one who was the best. Whoever it is, she was a somewhat close 2nd to Jadzia. And Kai Winn... perhaps one of the most wretched female characters ever seen in Star Trek. She could give the Wicked Witch of the West a run for her money. She seemed like the Bajoran equivalent of Armus- all their worst characteristics made hidebound.