But if you're seriously looking for the single most important, influential and innovative filmmaker in the history of the medium, there is but one man: D.W. Griffith. Yes, his best pictures are old. Really old. THE BIRTH OF A NATION is a struggle for many people to sit through (I personally found it quite engaging), and INTOLERANCE is an incomparable ordeal. But with those two films, Griffith laid the groundwork for every important "discover" that would follow. Lev Kuleshov's students penned the theory of montage after a copy of INTOLERANCE slipped through the censors. Almost every important director sites Griffith as an influence, and those who don't are only fooling themselves. Some say that there's been nothing original since Griffith, and while I tend to disagree, there's no doubt that almost everything springs from the original cinematic supergenius.
After Griffith, Sergei Eisenstein is doubtlessly the most influential director of all time. As I said above, the Kuleshov students "invented" montage after seeing INTOLERANCE; it was Eisenstein, however, who truly set the theory into stone. BATTLESHIP POTEMKIN is still often regarded as the greatest film ever made, though it has fallen down on the critics' lists somewhat in favor of CITIZEN KANE, LA REGLE DU JEU and the like. Certainly, no film is more studied than POTEMKIN internationally. And Eisenstein's six other films are all landmarks in their own right. His small body of work truly forms the heart of modern film tradition.
After Eisenstein? Here it gets difficult. I'd have to say that Charles Chaplin made the next greatest mark on the global film community, despite his many shortcomings. THE KID, THE GOLD RUSH, CITY LIGHTS and MODERN TIMES are some of the most enduring silent films (the last two's status as "silent films" beind somewhat in question). Chaplin was not a very significant person in the actual development of narrative film, however. Therefore, I'd have to stick both Jean Renoir and Orson Welles in after Eisenstein, and quite a ways ahead of Chaplin. Renoir's body of work is for me the most impressive of all directors. THE GRAND ILLUSION and THE RULES OF THE GAME are still two of the greatest films ever made; I might go so far as to call the latter THE greatest. Welles, however, probably made the greater impact. CITIZEN KANE, despite all arguments to the contrary, remains the most influential of all American sound pictures. THE MAGNIFICENT AMBERSONS would have been an equal masterpiece had so much of it not been lost. And TOUCH OF EVIL defined the film noir genre as well as any feature, before or since.
There are other names, as well, that should be added to such a list. John Ford was simply a titan - there's little that I can say about him, except that his masterpiece, THE SEARCHERS, sends chills down my spine to this day. And Bergman is my personal favorite, the director who speaks to me the most, and whose artistic vision I find the most intriguing. Both Andrei Tarkovsky and Sergei Paradjanov made quite an impact on me...particularly the former, whose ANDREI RUBLEV is one of the most treasured installments in my collection. And still others--Robert Bresson, Yasujiro Ozu, Akira Kurosawa, Satyajit Ray (you're right, it's a shame he's gone forgotten for so long), etc.--deserve to be acknowledged for their mighty contributions.
But Griffith and Eisenstein deserve the top spots, in that order, given the truly objective criteria. They simply changed EVERYTHING, and for ALL time. Every one of their films belong in an art museum, alongside the paintings of Rembrandt and Picasso (not that those painters works would be side by side, but you know what I mean).