This isn't linking their looks, but their careers,
Maria Sharapova and Britney Spears
Maria and Britney were both at their peaks when they were teenagers or very early twenties,
Maria got a sore shoulder and Britney had a mental breakdown and apart from the Wimbledon run
and the release of Femme Fatale, they've pretty much been a flop.
Dinara Safina and Floptina
Dinara flopped just as hard as Bionic
Serena Williams and Beyonce
Both with lots of Grammies (grand-slam titles) and best of their generation. Sung and competed in different era's and have slayed all your fav's. Although Run the World flopped, as did Serena's Wimbledon run. Expect a strong showing of sales (from beyonce) and wins (from serena) come spring.