Magnum P.I. - The moustache. The Hawaiian shirts. The chest hair. That description could be none other than Tom Selleck playing Magnum P.I. (of course, minus the Hawaiian shirt that could also just be a description of Tom Selleck in the 1980s.). Selleck plays Thomas Sullivan Magnum IV; a former Naval Intelligence Officer and Vietnam veteran turned private investigator who lives in the guest house of Robin’s Nest – an expensive ocean-side mansion on the island of Oahu, Hawaii.