THE MERCENARY
Directed by Sergio Corbucci, 1968
Starring Franco Nero
Score by Ennio Morricone
While not quite as seminal as Corbucci's 1966 classic Django (also starring Nero) or his later efforts-The Great Silence and Companeros--The Mercenary is a fun romp that populates the more comedic side of the Spaghetti Western cinescape.
It actually plays better on a second viewing, too (I watched it twice because at first the plot was a little confusing, which tends to be the case with a lot of these films).
Nero is charismatic beyond compare and co-star Tony Musante is fantastic as the "revolutionary" Paco. And then there is Jack Palance. His turn as the creepy jheri curled Curly is a scene stealer par excellance.
Corbucci's direction is pretty straightforward, but there are quite a few cool, recurring visual motifs. And Morricone's score is fantastic.
Additionally, if you are a Quentin Tarantino fan, this movie is mentioned throughout Once Upon A Time In Hollywood (Corbucci is name dropped a few times in that film, as well).