We discussed best films, favourite films... But what about the most important films? Please say what films impressed you most of all? What films changed your attitude to the cinema? What films changed world cinema (as you think)?
This is my list (no particular order):
"Battleship Potemkin" (Eisenstein)
"Un Chien Andalou" (Luis Bunuel) 
"8 1/2" (Fellini)
"Andrey Rublev" (Tarkovsky)
"The Color of Pomegranates" (Parajanov)