This iconic piece from Cartier, designed in the 1970s,  just keeps gaining in popularity. Available in white, yellow and rose gold, with or without diamonds, it requires the wearer to actually fasten it to the wrist with a screw (and accompanying screwdriver). Perhaps not the best choice if you like to change your jewellery frequently, but unutterbly chic. Available as shown here in white gold with diamonds for USD $9800.