Not sure if any would have been great, though quite possible; file them under great direcotrs. Eisenstein never finished Que Viva Mexico! or Ivan the Terrible Part III, and Bezhin Meadow wsa destroyed. Several of FW Murnau's German films are now lost, along with the later, Oscar nominated Four Devils. John Huston's documentary Let There Be Light has never been released on home video, anyone know the status?