Johnny Carson had the longest run of any "Tonight Show" Host, logging over 29 years behind the desk from October 1962 to May 1992. One could say that Carson sat behind two desks, as the show moved from New York City to Burbank, California in 1972. Before taking on the role, Carson hosted a game show called "Who Do You Trust?". It was there that he met emcee Ed McMahon, who’d join Carson for the entirety of his "Tonight Show" run as announcer and sidekick. McMahon was known for his nightly introduction: “Heeere’s Johnny!". "I am one of the lucky people in the world,” Carson said in his final Tonight Show sign-off. “I found something I always wanted to do, and I have enjoyed every single minute of it.”

Source: NBC