I think you’re exactly right, watch the silent comedies. Specifically, Buster Keaton, Charlie Chaplin and Harold Lloyd. Beware of Harry Langdon and Fatty Arbuckle, who just aren’t funny. All of these guys have a lot of great short films, particularly Chaplin’s early films for Mutual. But feature-wise, Chaplin’s first feature, The Kid; Keaton’s Our Hospitality and The General; and Lloyd’s The Freshman.