I think the Williams' sisters have beautiful bodies.  They might be on steroids (how the heck would I know), but their bodies don't suggest that to me.  There are a lot of tall, strong women out there - as suggested here - the Williams' are probably very lean.  At first, the media often portrayed them as hulking, scary beasts.  Then, the sisters got Avon contracts and the cover of Elle...
I don't see the appeal of Anna.  She's not exceptionally beautiful - I guess people think "She's pretty, for an ATHLETE."  (Whatever that means)
I think Keanu Reeves is sexy, face-wise and body-wise.  That lean, smooth, tawny body...  Brad Pitt is Fight Club-sexy AND Snatch-sexy AND Interview with the Vampire-sexy...