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Hilton…Simpson…Olsen…Spears…Duff…Kardashian…. Famous sisters are the best (and the worst). Celebrity siblings are all over the place right now, but we have always been interested in famous women who come in pairs. The Gabor sisters, The Landers sisters, Joan and Jackie Collins were duos previous generations kept tabs on.

Sisters are fun to watch: When sisters begin to share the spotlight sometimes they try to differentiate themselves from one another by establishing defining looks, such as Mary Kate and Ashley Olsen (dark boho vs sunny blond) or Jessica and Ashlee Simpson (sunny blond vs edgy rocker). We can witness them ease into their roles and equalize aesthetically (Olsens/ Simpsons).

Sisters are sexy: When sisters’ looks and attitudes diverge wildly, the game of:“which sister would you rather____?”is likely to ensue. When their looks converge, the pairing still provides fuel for fantasies.

Sisters are us: When one sister falters we can shift our hopes to the other one. When one seems appears to be the underdog, we can root for her.

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Though it is fascinating to watch sisters who are both in the public eye, it is refreshing to see a celebrity with her “normal” sister. Antonia Kidman is primarily a journalist, but glided into the public eye by accompanying Nicole to parties, premieres and shopping. Mia Farrow is the most widely known daughter of Maureen Sullivan, yet she has siblings with fantastic bone structure who remained somewhat unknown despite brushes with acting.  One of Mia’s sisters was the inspiration for the Beatles’ Dear Prudence.  Whatever a lesser known sister is up to, they offer a different perspective on her famous sibling. The citizen sister grounds her celebrity sister more than many interviews or magazine pieces can.

View this lightbox to see the full gamut of our favorite sisters.

Pictured: Peaches and Trixie Gelof vs. Catherine Deneuve and Françoise Dorléac, Lindsay Lohan and Ali Lohan vs. Maria Scicolone and Sophia Loren, Lisa Roberts Gilliam and Julia Roberts vs. Cameron Diaz and Chimene Diaz

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The red-carpet lovelies are enamored with the feminine designs of Gucci creative director, Frida Giannini. Her bold prints and subtle embellishment can be seen on starlets like Jennifer Garner (above), Cameron Diaz, and Gossip Girl’s Blake Lively. Garner perfectly modeled Giannini’s popular motif of black, white, and vibrant hues at Fox Searchlight’s premiere of Juno in Westwood, California. Want to see more ladies in Gucci? Click here.

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Justin Timberlake and Cameron Diaz attended the Shrek The Third photocall at Castel Sant’Angelo in Rome. Rumors surfaced earlier this year that ex-couple would be kept separate on the press tour for the film but the actors have seemed to have left the rocky past in the dust posing happily for pictures together. Do you think Timberlake and Diaz will get back together?

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Never one to take herself or her look too seriously, Cameron Diaz was crown princess in sea of fashion boredom at 2007 MTV Movie Awards in Universal City, California. After some recent questionable award show choices, Diaz reminded us of why we loved her so, showcasing her mile long legs in a very mini little black dress. What do you think of Diaz’ sexy style comeback?

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Cameron Diaz (in Chanel) hammed-it-up with co-stars Amy Sedaris (L) and Amy Poehler (R) at the premiere of Shrek The Third in Los Angeles. Diaz kept the mood light even though she had to share the red carpet with recent ex-boyfriend/ co-star Justin Timberlake but she was a gracious ex-girlfriend posing for cast photos and sharing a friendly hug and a kiss with Timberlake.