|Star Trek: Where No Man Has Gone Before (1966) [Lt. Cmdr. Gary Mitchell]: Crushed to death/buried alive when William Shatner uses a laser rifle to bring down a landslide on top of Gary as Gary starts to climb out of an empty grave.
2001: A Space Odyssey (1968) [Dr. Frank Poole]: Set adrift in the vacuum of space when the computer HAL-9000 cuts his lifeline outside the station.
Firecreek (1968) [Earl]: Shot to death in a shoot-out with James Stewart. (Thanks to Brian)
Barnaby Jones: Sunday: Doomsday (1973) [Howard Lee]: Shot in the chest in a shoot-out with Buddy Ebsen.
The Wild Pair (1987) [Captain Kramer]: Neck snapped by Bubba Smith. (Thanks to Kyle)