Classic early Knotts was as nervous Brain Surgeon and Bomb Squad guy on Steve Allen, and bits in "No Time for Sergeants" and "Move Over Darling" (as the shoe salesman Doris Day pays to pretend he, not Chuck Conners, was stranded on an island with her so as to not make hubby James Garner jealous).

Great montage at https://www.youtube.com/watch?v=lhWa7o1sP1k

It was said that off-camera, Knotts had the easy charm and Griffith the more nervous and less-approachable one.