Los cautivos

Boetticher and Scott spent the latter half of the 1950s making some terrific, adult, low-key Westerns, of which this stands as the best. Atmosphere, technical work and acting are all excellent, with interesting villain characterizations and a well-realized flawed hero in Scott.

Brutal and vivid, great-looking, and among Elmore Leonard's earliest writing work in the medium. Check out this classic, as well as the other films of the star and director (also the similar, excellent Gary Cooper/Anthony Mann teaming in the following year's Man of the West.)