Julia Cavendish tops my list. A regal beauty.
We've had this discussion elsewhere and Dorothy Harder always gets honorable mention. So does Jean Hippach.
Leila Meyer may not have been exactly beautiful, by our standards, but she was certainly exotic and attractive.
Virginia Clark has been described as a beauty, and one certainly gets the impression she was attractive to men, but the only image I've seen of her was the passport photo in Gallery of Titanic Visages. In that photo, she certainly doesn't look beautiful, though slim and dark-haired. I like to think it was just an unflattering photo - which passport photos tend to be (with all the hundreds they must look at each day, airport check-in people still exclaim over mine!).
And I remember many of us were pleasantly surprised at how attractive Bertha Chambers was when G of TV came out.
Differences in standards between the generations are apparent when you look at photos of some of these passengers. I have the impression that the senior Lucile Carter was known for her looks (she was at least known for her fashion sense) but most photos show her looking rather matronly. And then Berthe DeVilliers made her living on the basis of her attractiveness, but photos seem to show a rather heavy-set, hard-featured woman. Looks to me like her attractiveness lay elsewhere...
Violet Jessop was definitely beautiful, as was said earlier. I'm trying to think of which other ladies of the crew and second and third class passengers were lookers. Nellie Hocking comes to mind, and Ada Clark looks like she has a rather winsome quality to her, though I haven't seen enough photos of her to really get a sense. Judith Geller described Jane Quick as attractive.
Really, there were very many good-looking people on the ship. But I vowed to quit writing such long posts.