As part of YouTube's entry into the online movie-streaming business, it has created something called OpenFlix -- a collection currently boasting 670 free, full-length movies. As far as I can tell, they're all public domain films -- but some are classics, and worth a look. They all have ads at the beginning and periodically throughout the feature. Many of these are also available (commercial-free, but not in the convenient YouTube format) at Archive.org's Moving Image Archive.
Night Of The Living Dead
"Follows Ben (Duane Jones), Barbra (Judith O'Dea), and five others, who are trapped in a rural farmhouse in Pennsylvania and attempt to survive the night while the house is being attacked by mysteriously reanimated ghouls, otherwise known as zombies." (NOTE: although this is available in 1080p, the video quality isn't real hot. Looks better than the VHS I watched it on as a kid, though.)
"Inspired by true events, this film tells the story of the riot that occurred on the battleship Potemkin when the crew was given rotten meat for dinner. Their protest soon turns into a riot when the sailors raises the red flag in an attempt to set off a revolution in the port of Odessa."
Man with a Movie Camera
"Original title: Chelovek s kino-apparatom. This experimental film is really three in one: a documentary of a day in the life of the Soviet Union, a documentary of the filming of that documentary and a depiction of an audience watching that documentary. We see the cameraman and the editing of the film, but what we don't see is any of the film itself. With English subtitles." (NOTE: this is a silent film, though there are other versions out there with sound added.)
"** IMDB #58 Best Movie Of All Time ** in High Def
M - Eine Stadt sucht einen Moerder (1931)
When the police in a German city are unable to catch a child-murderer, other criminals join in the manhunt."
Nanook Of The North
"Widely held as the first anthropological documentary film ever made, it documents a year in the life of an Inuit Eskimo (Nanook) and his family." Hey, it's the Criterion Collection version!
Making a Living (Charlie Chaplin)
"Early Charlie Chaplin Short Film." Also known as "Charlie Chaplin grifts various people in 1914 while sporting a full mustache; hijinks ensue."
"**Nominated for 2 Oscars ** Animated featured based on the novel by Jonathan Swift. Gulliver lands on Lilliput and tries to prevent war between that tiny kingdom and its equally-miniscule rival, Blefiscu, as well as play matchmaker between the Princess and Prince of the opposing lands. The Lilliputian town crier and general fussbudget Gabby helps him and then doesn't. A dangerous situation arises when Blefiscu spies, Sneak, Snoop, and Snitch, steal Gulliver's pistol."
The Fast and the Furious
No, not that "Fast and the Furious." This is the old (ahem, classic?) one. "Wrongly imprisoned for murder, Frank Webster (John Ireland) breaks out of jail to try and clear his name. With the police in hot pursuit, he's forced to take a beautiful young woman (Dorothy Malone) in a fast sports car hostage. Together they slip into a cross-border car race in an attempt to make it to Mexico before the police catch up."
In The Year 2889
"A group of post atomic war survivors are hunted by cannibalistic human mutants with telepathic powers." WARNING: this is a very bad movie.
(Via the most excellent @brainpicker.)