By far the most beautiful of the Pretty Little Liars
She really is the most gorgeous girl on the show, by far. Not that she has much competition -- apart from the actress who plays Alison, who is equally attractive as Ashley, but doesn't count if we restrict it to "main" cast.
Among the Liars, only the girl who plays Aria is at all pretty as well, although not in Ashley's league. The other two are really quite unattractive, and the rest of the cast members are even less appealing.
It's really Hanna/Ashley's show.
It helps that her character is also by far the most likable, and the one you empathize with the most. Aria has her moments too, but the other two Liars are very unappealing characters, so that makes Hanna even more the point of attention.
Oh, and the fact that she has the best wardrobe helps as well.