If you are interested in a good Mexican film to watch in honor of Cinco de Mayo then look furhter than Los Olvidados (The Forgotten Ones). Directed by Luis Buñuel, this 1950 film follows a group of children who live in the slums of Mexico City. The film combines neo-realist and surrealist elements to tell the story of this street gang.
Los Olvidados is the film that earned Buñuel international recognition; he won the Best Director prize at the 1951 Cannes Film Festival. It is considered to be one of the greatest Mexican films of all time.
Buñuel would direct films in Mexico until 1955 and they are definitely worth checking out. I, for one, will be revisiting Los Olvidados as research for my thesis.