|Alfred Hitchcock Presents: The $2,000,000 Defense (1958) [Mark Robeson]: Reportedly killed by Leslie Nielsen. (I haven't seen this episode myself, but got the information from an episode guide.)
Pyro (Fuego; Pyro...The Thing Without a Face; Wheel of Fire) (1964) [Vance Pierson]: Commits suicide by jumping from a ferris wheel when cornered by police, after Soledad Miranda tries to talk him into surrendering.
Johnny Belinda (1967) [Black MacDonald]: Presumably killed in a struggle with David Carradine. (I haven't seen this version myself, but I have seen Charles Bickford's death in the 1948 version.)
Take a Hard Ride (La Parola di un fuorilegge...e legge!) (1975) [Kane]: Reportedly shot in the back by Lee Van Cleef. (I haven't seen this movie myself.) (Thanks to Michael)