This one's pretty durn funny: Dana Andrews as Matt Cvetic in I Was a Communist for the FBI (April 23, 1952).
And, of course, a 15-minute episode of Vic and Sade: "Manual for Wives" (February 2, 1941). Wait for the Latin.
Update: Best line from IWACFTFBI: "I went back to my room and boned up a little on the Communist Manifesto."
Update II: Oh yeah, you need Quicktime to play the shows. It's fwee! It's fwee!