Audemars Piguet’s Royal Oak, one of the world’s most coveted best replica watches, celebrates its 50th birthday this year with a flurry of special editions. The late Gérald Genta’s groundbreaking design, with its bolted octagonal bezel and integrated steel bracelet, succeeded in creating the luxury sports watch category that dominates the market today. “I love iconic shapes and the Royal Oak is not only iconic but genderless, which I love,” says Serena Williams, who frequently sports a Royal Oak, both on and off court. She is just one of a legion of celebrity fans of both sexes including Jay Z, Karl Lagerfeld and Ashley Olsen, yet one little celebrated fact…