|North by Northwest (1959) [Leonard]: Shot to death by a police sharpshooter as Martin is trying to knock Cary Grant off of Mount Rushmore.
Bonanza: The Gift (1961) [Emeliano]: Shot by Jim Davis; he dies shortly afterwards while talking to Lorne Greene. (Thanks to Gordon)
Stagecoach to Dancers' Rock (1962) [Dade Coleman]: Shot to death by a wounded stagecoach driver, who had mistaken Martin for an attacking Apache. (Thanks to Gordon)
Cleopatra (1963) [Rufio]: Commits suicide (off-screen) by throwing himself on his sword in the desert; his body is shown afterwards when Richard Burton discovers him in the abandoned camp. (Thanks to Vladimir and Stephen)
The Outer Limits: The Man Who Was Never Born (1963) [Andro]: Ceases to exist when he attempts to return to his own time, after he had prevented that timeline from coming about by preventing the marriage of John Considine and Shirley Knight. (Thanks to Stephen)
The Wild Wild West: The Night of the Red-Eyed Madman (1965) [General Grimm]: Stabbed in the back when he gets knocked into a blade sticking out of the wall during a fight with Robert Conrad.
Nevada Smith (1966) [Jesse Coe]: Stabbed to death in a knife-fight with Steve McQueen. (Thanks to Bob)
Mission: Impossible: The Council Part 2 (1967) [Rollin Hand/Frank Wayne]: Playing a dual role as both his regular character "Rollin" and a surgically-altered look-alike "Frank," "Frank" is shot twice in the chest by Robert Phillips. (Thanks to Dignan)
They Call Me MISTER Tibbs! (1970) [Logan Sharpe]: Commits suicide by running in front of a truck, rather than be arrested by Sidney Poitier.
Meteor (1979) [Major General Adlon]: Crushed to death by falling rubble when the meteor strikes; his body is shown afterwards when Sean Connery discovers him. (Thanks to Tommy)
Without Warning (1980) [Fred 'Sarge' Dobbs]: Blood drained when the alien (Kevin Peter Hall) throws its fanged disc at his chest. (Thanks to Martin and Dignan)
The Fall of the House of Usher (1982) [Roderick Usher]: Crushed to death when the house collapses around him while he's struggling with his sister (Dimitra Arliss). (Thanks to PortsGuy)
Murder, She Wrote: Birds of a Feather (1984) [Al Drake]: Shot in the chest (off-screen) by Gabe Kaplan in Martin's office; his body is shown afterwards when Jeff Conaway discovers him.
12:01 (1993) [Dr. Thadius Moxley]: Explodes after being hit in the chest by an energy beam from his experimental super-accelerator, when he falls into the beam's path after a struggle with Jonathan Silverman.
Ed Wood (1994) [Bela Lugosi]: Dies (off-screen) of a heart attack; his body is shown afterwards lying in his coffin during his funeral.
The X Files (1998) [Alvin Kurtzweil, MD]: Killed (off-screen) by John Neville's men. We last see Martin as the men surround him in an alley; his death is confirmed is a later conversation between John and David Duchovny. (Thanks to Stephen)
Sleepy Hollow (1999) [Peter Van Garrett]: Decapitated (off-screen) by the Headless Horseman (Ray Park/Christopher Walken) after the Horseman ambushes Martin's carriage; the scene cuts away just as the Horseman strikes.
In the Beginning (2000) [Abraham]: Dies of old age/natural causes, after being carried out of his tent. (Thanks to Hamish)
The Majestic (2001) [Harry Trimble]: Dies of a heart attack. (Thanks to Jacob)
Without a Trace: When Darkness Falls (2005) [Frank Malone]: Dies of old age/natural causes. (Thanks to PortsGuy)
City of Ember (2008) [Sul]: Drowned when he holds the water turbine in place, sacrificing himself to allow Saoirse Ronan, Harry Treadaway, and Amy/Catherine Quinn to escape. (Thanks to ND)
9 (2009; animated) : Providing the voice of a robotic sack-creature, his soul is sucked out of his body by the BRAIN machine after 9 (voiced by Elijah Wood) accidentally attaches the talisman to the machine. His soul later reappears when 9 releases it. (Thanks to Tommy)