Aguirre, the Wrath of God (1972)

Wikipedia mentions that Werner Herzog wanted Klaus Kinski for the role of the title character after remembering his ‘terrifying and deranged antics’ during the three months he roomed with Herzog’s family. That statement truly sets up the expectations for this film about a crazed conquistador who stages a coup to lead a doomed mission searching for the treasures of El Dorado. There’s not much to say beyond that. The film is never boring and ever other character is overshadowed by Kinski’s madman.