I wonder whether Cleopatra actually was beautiful by today's standards, or even the standards of her time, or if it just suited people to flatter such a powerful woman. Incidentally, as far as inner beauty goes, Cleopatra used to have her pregnant slave girls murdered and dissected so she could observe what babies looked like at different stages of development.
If you were interested in a reference for that, I can't access the book any more because I'm no longer at uni but here is a review of it.
Depends what you see as beautiful. Liz Taylor was stunning, but lived a very lonely life. Grace Kelly was incredibly beautiful and graceful but her life came to a sudden halt. I guess it should be measured in outer and inner beauty, which in that case I would say Nicole Kidman!
I thought Ava Gardner was rather gorgeous (from head to toe). Liz Taylor was very pretty but very short and stacked on the weight really quickly (probably because of the booze and her love for chicken skin). Grace Kelly however, always impressed me because she was so fine, so delicate and so seemingly conservative. But I still think that Ava Gardner was a classic beauty (despite the booze and the Spanish men friends).