Jay Leno and David Letterman are two of the most iconic late night talk show HOSTS in television history. Leno hosted 'The Tonight Show' from 1992 to 2014, while Letterman hosted 'Late Night' from 1982 to 2015. Both shows featured a mix of celebrity interviews, comedy sketches, and musical performances. They were both known for their quick wit and sharp humor, and their shows remain popular in syndication.