|Nicholas and Alexandra (1971) [Rasputin]: Poisoned, shot in the back, and beaten by assassins, then drowned (off-screen) after being thrown into the river. (The scene ends during the beating; the remainder of Rasputin's murder occurs off-screen.)
The Mutations (The Freakmaker) (1973) [Lynch]: It's been a long time since I've seen this movie, so my memory is vague, but I believe that he was beaten to death by the enraged circus "freaks."
The Vault of Horror (Tales from the Crypt Part II) (1973) [Moore]: Hit by a car while crossing the street, caused by his "voodoo portrait" simultaneously being "mutilated" by a turpentine spill.
The Golden Voyage of Sinbad (1974) [Koura]: Stabbed in the stomach during a swordfight with John Phillip Law, then falls into a mystical fountain (which suddenly becomes a fountain of blood after he falls in).
Doctor Who: Logopolis (1981) [The Doctor]: Fatally injured in a fall from a radio tower during a struggle with Anthony Ainley; his body "regenerates" and transforms into Peter Davison. (I wasn't sure whether to include this or not, since it's only arguably the "death" of the Tom Baker incarnation of the character and not the death of the character itself, but in the end I decided to go ahead and list it.)
Black Adder II: Potato (1986) [Captain Redbeard Rum]: Killed (off-screen) in a battle with Australian aborigines; we only learn what happened when Rowan Atkinson informs Miranda Richardson of his death after Rowan makes it safely back to England.
Marple: Towards Zero (2007) [Frederick Treves]: Dies of a heart attack (off-screen) while climbing the staircase in his hotel; his body is shown lying on the floor afterwards. It's later revealed that Greg Wise had deliberately placed an "Out of Order" sign on the working elevator in the hopes of forcing Tom to overexert himself. (Thanks to Brian)