Casablanca
One of the greatest stories of tragic love ever cast onto the silver screen, Casablanca stood model for Mos Eisley and its scum and villany.
Edgar Rice Burroughs might have stood on the shoulders of earlier 'officer adventures on Mars' tales, but his distinct style and sense of storytelling has cemented his place in the history of adventure stories. Here we meet John Carter and his martian bride to be, Dejah Thoris, and their planet-spanning escapades.
Swept by magic carpet to the glorious planet of Mars, no sooner has Lt. Gullivar Jones fallen for the beautiful Princess Heru of the Hither people before she is kidnapped by the hideous Tither people. Gullivar pursues in bumbling fashion, in an adventure across the jungles and rivers of Mars. John Carter takes notes.
Torn out of his days cruising the streets of Modesto, American Graffiti is Lucas's love letter to a long since dead mating ritual. Seeming perhaps a sidestep in relation to Star Wars, when compared to the science fiction worlds of THX 1138, it was crucial in shaping the populist approach with which Star Wars conquered the world.
WWII was an enormous influence on all kids of the 50s and 60s, and Lucas was no exception. From the general good vs evil nature of the conflict to the specifics of war epics like The Guns of Navarone and air-heroics of The Dam Busters and 633 Squadron, it seems entirely possible that Star Wars would never have existed if not for the war.