|Dead Eyes of London (Die Toten Augen von London; Dark Eyes of London) (1961) [Edgar Strauss]: Pushed through a window by Wolfgang Lukschy.
The Counterfeit Traitor (1962) [Kindler]: I've only seen part of this movie (and didn't seen Klaus' part), but the IMDB identifies his role as "Kindler, Jewish refugee who dies in fishing boat."
The Indian Scarf (Das Indische Tuch) (1963) [Peter Ross]: Strangled with a scarf (off-screen) by Hans Clarin; his body is shown afterwards encased in a plaster statue. (Thanks to Andrea)
For a Few Dollars More (Per qualche dollaro in piu) (1965) [Wild, the Hunchback]: Shot to death in a gunfight with Lee Van Cleef in a tavern. (Thanks to Robert)
Grand Slam (Ad ogni costo; Top Job) (1967) [Erich Weiss]: Shot to death by Adolfo Celi by the harbor. (Thanks to Andrea)
The Great Silence (Il Grande silenzio; The Big Silence) (1969) [Tigrero a.k.a. Loco]: Althoguh he survives in the actual movie, an alternate "happy ending" was filmed for different markets; in the alternate ending (included in the DVD), he is shot in the head by Frank Wolff. (Thanks to Andrea)
Venus in Furs (Paroxismus; Black Angel) (1969) [Ahmed Kortobawi]: Killed by Maria Rohm's ghost, using her supernatural powers, while he's bound and suspended by his wrists.
Count Dracula (El Conde Dracula) (1970) [Renfield]: Dies in an asylum. (Thanks to Andrea)
Showdown for a Bad Man (Per una bara piena di dollari; A Barrel Full of Dollars; Coffin Full of Dollars; Nevada Kid) (1971) [Hagen]: Falls to his death from a bell tower after being shot by Jeff Cameron. (Thanks to Andrea)
Aguirre, the Wrath of God (Aguirre, der Zorn Gottes) (1972) [Don Lope de Aguirre]: Presumably killed (off-screen) either by natives or monkeys. The movie ends with him standing alone on the boat after everyone else is dead, while the monkeys overrun the boat; the implication of his fate is pretty clear.
Shanghai Joe (Il Mio name e Shanghai Joe; The Dragon Strikes Back; The Fighting Fists of Shanghai Joe; My Name Is Shanghai Joe) (1972) [Scalper Jack]: Stabbed in the chest with his own knives by Chan Lee. (Thanks to Andrea)
Death Smiles on a Murderer (La Morte ha sorriso all'assassino) (1973) [Dr. Sturges]: Strangled with a cord by Luciano Rossi. (Thanks to Andrea)
Operation Thunderbolt (Mivtsa Yonatan) (1977) [Wilfried Boese]: Machine-gunned by Israeli soldiers during the raid on the terrorists' hideout.
Nosferatu the Vampyre (Nosferatu: Phantom der Nacht) (1979) [Count Dracula]: Killed by the rays of the rising sun after Isabelle Adjani tricks him into staying out past sunrise by setting herself out as bait.
Venom (1982) [Jacques Muller a.k.a. Jacmel]: Shot repeatedly by police sharp-shooters when he staggers out onto the balcony after being bitten by the black mamba.