Dabney Coleman had the rare quality of buffoon seriousness.
I am familiar with him specifically, as 9 to 5 was my favorite movie for a time. That movie was produced around the late 70's and early 80's. Peak Dabney Coleman era.
Some of his first tv appearances were on bangers like The Alfred Hitchcock Hour, The Outer Limits, The Fugitive, I Dream of Jeannie.
Midway, On Golden Pond, North Dallas Forty, The Trouble with Girls, Melvin and Howard, WarGames. That is but the tip of the iceberg. There are hidden gems in his filmography.