Stephen Root. His IMDB listing is nothing short of astonishing, with range that will shame most leading actors. From Milton in “Office Space” to the a political operative in “The West Wing” to and insane judge in “Idiocracy”
John Dehner, who often played the bad guy, possibly best known as Pat Garrett opposite Paul Newman as Billy the Kid in “The Lefthanded Gun” or as the mill owner in “Carousel.” He also did comedic roles, and was great as Jane Fonda’s father in “Fun With Dick and Jane,” especially in the scene in which George Segal tries to beg money from him and Dehner explains how he’s jealous at how lucky Segal is to be challenged with financial difficulty.
Margot Martindale. She’s been in tons of things but I first really noticed her in a segment of Paris, je t’aime, where she got to shine as a lonely but awed American sightseeing around Paris. She’s narrating, reading her journal to her French club buddies back home. Her French is atrocious and when she tries to speak to a local they gently guide her into speaking English, which is a bit frustrating if you’re trying to practice your French. It’s a short but sweet, delicate and melancholy little thing, on YouTube.
Charles Lane, of course. 364 acting credits. During the 1930s and 40s, he would appear in a dozen movies a year (19 in 1937, for example), usually with just one or two lines. He would often go to one studio in the morning, do his scene, then go to another studio to do his scene in the afternoon.
His voice and face are unmistakable: he had a ratchety voice and he’s always described at “hatchet-faced,” with a nose like a beak. When he wasn’t just some guy with one line, he played a grouchy banker type.
His best-known film was It’s a Wonderful Life as one of Potter’s flunkies. His closest thing to a major role was as Homer Bedloe, the villain in Petticoat Junction
I second this. He’s always a hoot. I particularly liked him as Gaston Means in Boardwalk Empire; he’s also the voice of Bill Dauterive in King of the Hill.
My favorite character actor is Nicholas Pryor. He’s better known for his T.V. roles than for movies, although he has quite a few film credits. You might recognize him as Tom Cruise’s father in Risky Business, but you definitely know his face if you’ve watched T.V. at all since 1954.
Percy Helton. Short bald guy with a raspy, breathless voice. I always picture him as the night clerk on duty in a dingy hotel when the hard-boiled noir gumshoe bursts in and says “*Where’s *Murphy?” Percy replies: “Oh, Mr Murphy? He just went up the stairs!”
Robert Easton, the lanky blonde guy with the prominent Adam’s apple who was typecast as a Texan/Southerner/Hillbilly. I was bowled over when I learned he played the Klingon High Judge in Star Trek VI: The Undiscovered Country.
Leonid Kinsey. Played Sasha the bartender in*** Casablanca***, but I remember him best for acting alongside the Three Stooges in at least one short, and as POW Vladimir Minsk in the Hogan’s Heroes pilot. He really was born in Russia and emigrated after the Bolshevik Revolution.
Kathleen Freeman. She bore enough of a facial resemblance to Loretta Swit that for a long time I thought they were related, maybe mother and daughter.
Excellent actor; he was good in Pleasantville, too. But I loathe the character of Col. Markinson.
J.K. Simmons - Dr. Skoda in Law & Order, J. Jonah Jameson in Spider-Man, and (hysterically) Cave Johnson in Portal 2.
Bruce Boa - A colonel in Full Metal Jacket (“Son, all I’ve ever asked of my marines is that they obey my orders as they would the word of God.”) and a demanding guest who wants a Waldorf Salad at Fawlty Towers.