Well, Bergman is known for films like The Seventh Seal, The Virgin Spring, Wild Strawberries, Persona, Cries and Whispers or From the Life of the Marionettes (that's just a sample, he directed more than 40 films). Several of his early films star Max von Sydow in major or minor roles.
He's often seen as a very artsy and intellectual director, partly because of the existentialist themes that permeate most of his movies, but in fact a movie like The Seventh Seal is short, entertaining, and was never envisaged as high art when it was directed. In any case, he's considered a very influential director, and got numerous praised by directors as diverse as Scorcese, Coppola, Woody Allen, Kubrick, Almodovar, Tarkovsky or Spielberg.
Carl Theodor Dreyer was less prolific, directing only 14 films, often in countries other than Denmark, and mostly in the silent era —but he did make a few sound films that are often highly regarded among film-buffs, notably Vampyr and The Word/Ordet.
