Directed by F. W. Murnau and released in 1922, Nosferatu, A Symphony of Horror (Nosferatu, Eine Symphonie Des Grauen) is a loose adaptation of Dracula - Bram Stoker's widow was notoriously protective of copyright, and as this was an unauthorised adaptation, the names were changed to protect the guilty. So Harker becomes Hutter, Mina becomes Ellen, and London is swapped for Bremen, and Murnau adds a few little touches of his own, casting Nosferatu as the cause of the 1838 outbreak of plague in Bremen.
The plot is essentially a streamlined form of Dracula - an estate agent, Hutter (Gustav von Wangenheim), is sent to see Count Orlok (Max Schreck) to help him with a purchase in Bremen. Turns out the Count is buying the dilapidated houses directly opposite where Hutter lives. The Count develops a fancy for Hutter's wife, Ellen (Greta Schröder) and heads to Bremen, bringing with him the plague. Hutter naturally wants to stop the Count, but can he? The likes of Dr Seward, Arthur Holmwood and even Van Helsing are excised from the plot to make room for the larger than life Count Orlok.
Nosferatu is usually figured with Der Golem and The Cabinet of Dr Caligari has being one of the Big Three of German Expressionism (Metropolis sometimes replaces Der Golem), a film movement that grew out of the art movement of the same name after the First World War. These films are sometimes referred to as the first horror films, and they certainly had an effect on later filmmakers, most notably for their use of light and shade, and the manipulation of shadow through careful lighting. One thing that should be noted is the fact that most of the early German Expressionist films were made in studios, so filmmakers could control the filming conditions, but Murnau took Nosferatu outside. The coach trip through the woods as Hutter travels to the castle is filmed in negative, using stop motion animation, to give a jerky, otherworldly feel to the journey. It looks unreal because Hutter is in an unreal space.
Other visual devices have cropped up throughout the years, from Count Orlok's incredibly creepy way of standing up to the distortions caused by projecting his shadow across a wall. Plus, this is not the sexy, romantic vampire of post-Anne Rice fiction - Orlok is an ugly, ratty creature who brings only death and disease. There is no promise of love and everlasting life here. Later portrayals of Dracula show him as being a charismatic figure, if not necessarily physically attractive, but here we really get the sense of the vampire as being something abject and monstrous.
The film is now in the public domain so I've embedded the link to the full film below.