Dorothy and her ruby slippers are much more influential than Darth Vader and his respirator. At least that's what one study says: According to findings by Applied Network Science, 1939's The Wizard of Oz has had a greater impact on filmmaking than 1977's Star Wars, although it should be noted that the sci-fi classic does rank second on the overall list.
You could even say that George Lucas' first Star Wars share more than a few similarities with The Wizard of Oz. Think about it — A New Hope is about a central protagonist raised by their aunt and uncle, living the simple life on a farm, and wanting more out of the world, when they are drawn into a fantastical adventure and pitted against a purely evil (and magic-using) antagonist.
The overall study (given the somewhat cumbersome title of "Identification of Key Films and Personalities in the History of Cinema from a Western Perspective") looked to seek a new way of categorizing movie successes via how much they influenced other films after they were released.
This is in contrast to more well-known ranking systems like box office numbers or critic/audience reviews. Using IMDb as a base, the study looked at a number of different movie factors, including year of release, country of origin, directors, actors, and genre in order to extrapolate patterns and trends of influence.
Out of the Top 20 most-influential films ever produced, more than half are genre fare like Jaws, 2001: A Space Odyssey, King Kong, Psycho, Frankenstein, Metropolis, and Snow White and the Seven Dwarfs.
The list of directors is equally full of genre veterans, with Alfred Hitchcock and Steven Spielberg taking the top two spots, respectively. Stanley Kubrick, Fritz Lang, David Cronenberg, Robert Rodriguez, Tim Burton, and John Carpenter are also mentioned.
When it came to actors, names like Samuel L. Jackson, Harrison Ford, Tom Cruise, Arnold Schwarzenegger, Carrie Fisher, Judy Garland, Jamie Lee Curtis, and Sigourney Weaver all ranked high as well.
Interestingly, the top four most influential sci-fi actors are Japanese: Kenji Sahara, Haruo Nakajima, Yoshifumi Tajima, and Katsumi Tezuka. What they have in common is the fact that they all appeared in Japanese kaiju films of the '50s and '60s (e.g. Godzilla), a genre that's had a major impact on American monster flicks. In fact, Japan and its actors ranked so highly with the study pretty much based on that fact.
Some of those Japanese actors had also been involved with movies directed by hailed director Akira Kurosawa, whose enduring influence can be seen in everything from The Magnificent Seven to Star Wars to Westworld.