The Royal Oak Offshore Selfwinding 43 mm is the big brother to the original Royal Oak that set this whole genre on its head. This 42 mm chronograph runs to chronometer grade precision, while the integrated bracelet holds its own with the best of this elite category. $19,400 Omega Speedmaster Moonwatch Professional Image Credit: Courtesy of Grand Seiko This one is big at 44.5 mm, precise, lightweight and complicated.