For me it's the 'spaghetti' westerns that hit the spot. Sergio Leone is a master but I've only seen his more known / acclaimed films: The Good, the Bad and the Ugly Fistful of Dollars and Once Upon a Time in the West
So my entry for best film that is maybe a little more obscure, and with a great sing-along theme tune, Vamos a matar, compañeros:
The lyrics (if you understand Spanish, even better
Levantando al aire los sombreros
Vamos a matar, vamos a matar, compañeros
Pintaremos de rojo sol y cielo
Vamos a matar, vamos a matar, compañeros
Hay que ganar muriendo, pistoleros
Vamos a matar, vamos a matar, compañeros
Hay que morir venciendo, guerrilleros
Vamos a matar, vamos a matar, compañeros
Luchando con el hambre, sin dinero
Vamos a matar, vamos a matar, compañeros
Estudiantes, rebeldes, bandoleros
Vamos a matar, vamos a matar, compañeros
Hermanos somos, reyes y obreros
Vamos a matar, vamos a matar, compañeros.


