 In his 80s, Nielsen performed serious roles on screen and stage (such as his one-man theatre show "Darrow", in which he played Clarence Darrow), as well as providing voice-overs and appearances for commercials (including spots for a credit union in Arizona, where he owned a secondary residence), cartoons such as "Zeroman", where he had the leading role/voice, children's shows, such as "Pumper Pups", which he narrated, and comedic film roles.The sibling relationship with his elder brother, the Honourable Erik Nielsen, a former Deputy Prime Minister of Canada, served as the premise of an HBO mockumentary entitled "The Canadian Conspiracy" in which Leslie Nielsen appeared, along with other prominent Canadian-born media personalities.He was a celebrity contestant on CBS's "Gameshow Marathon", where he played "The Price Is Right", "Let's Make a Deal", "Beat the Clock", and "Press Your Luck" for charity.