What is it that makes a woman truly sexy [details inside]?

What is it that makes a woman truly sexy, her dress, attitude, or her physical beauty? If a so-so looking woman dressed sexy (assuming she had the body to pull it off) and had a sexy attitude would she be more or less sexy than a woman who was physically beautiful, dressed sexy but had the attitude of a pit bull crossed with an alligator? Could a woman with a sexy attitude and physically beautiful face and body be sexy if she did not dress sexy at all? Where does the sexiness of women really come from or is it in the eye of the beholder or the media?