20. For decades, this 'that guy' had one-episode parts in many TV shows, including "Barney Miller" (1978-1979), "Simon & Simon" (1985), and "McCloud" (1976). He also played the recurring role of Silvermane in "Spider-Man" (1995-1997).
From Quiz I'm Not an Actor, But I Play One on TV
Answer:
Jeff Corey
Born in 1914 in Brooklyn, New York, Corey lived a fascinating life. Hooked on show business in high school, he got a scholarship to the Feagin School of Dramatic Arts - one of the top performing arts school in New York at the time.
After school, Corey spent his time on stage until his first film in 1939, "One Third of a Nation".
In 1943, during World War II, Corey joined the United States Navy Photographic Service and was assigned to the Yorktown. One of three citations he received was for a photo series of a kamikaze attack on his ship, the aircraft carrier Yorktown.
Corey resumed his acting career after the war, until 1951, when he was called to appear before the House Committee on Un-American Activities. Refusing to name anyone else, Corey was blacklisted.
Not allowed to act, Corey wound up starting a speech and acting class in his garage. The business grew until it was housed in a small theater and Corey had become one of the top acting coaches of his day. His students were a veritable who's who of Hollywood and included James Dean, Penny Marshall, Leonard Nimoy, Anthony Perkins, Robin Williams, and Jack Nicholson, among many others.
After the blacklisting was lifted around 1960, Corey returned to his acting career, and continued teaching as well.