Battleship Potemkin

This film is considered one of the most important of the silent films. The Battleship Potemkin is a Russian movie directed by Sergei Eisenstein and released in 1925. There is a good overview of the film's history and significance here. Roger Ebert concludes his analysis by saying,

``Battleship Potemkin'' is no longer considered the greatest film ever made, but it is obligatory for anyone interested in film history...

It is available for sale on DVD and can be viewed online or downloaded free at the Internet Archive, viewed online at jonhs.net or viewed at googlevideo:

update 2/10/2008: the googlevideo originally embedded here is no longer available, but here's another: