Whenever designers dabble in 1970s retro, they inevitably name-check Farrah Fawcett — the actress who helped define style in the latter half of the decade. When she made her debut as athletic private investigator Jill Munroe on the TV series Charlie's Angels in 1976, she brought with her the first must-have celebrity hairstyle — a mass of big blond hair, feathered and layered with curls. The so-called "Farrah Flick" brought her recognition, but it was her high-waisted denim flares and disdain of bras that made her the decade's most famous sex kitten. The pin-up of Fawcett wearing a red bathing suit, with her head cocked back, has reportedly been purchased more than 12 million times, making it the best-selling poster of all time.