• Internet Archives - Feature Films - When you’re looking for free movies online, the Internet Archive should be your first stop. It features large collections of classic comedies, film noir and sci-fi/horror flix. Many films listed below come from the Internet Archive.
• Google Video - For some time now, major classics have appeared on Google’s site. You will find many such films above.
• Australian Screen Archive - The Australian National Film and Sound Archive provides free and worldwide access to over 1,000 film and television titles – a treasure chest of down-under video 100 years in the making.
• B Minus Movies - AMC is your new go-to site for B-movies by the likes of John Carpenter (Dark Star) and Roger Corman (Saga of the Viking Women). Want to see international icons before they made it big? Check out Raquel Welch in A Swingin’ Summer or kung-fu king Sonny Chiba in Terror Beneath the Sea. Looking for the unexpected? How about The Ruthless Four, a spaghetti Western starring Klaus Kinski.
• Big Five Glories - Presents classic films in the public domain within an attractive user interface. Makes the films a pleasure to watch.
• Clear Bits - This new site provides hosting and distribution for open licensed (Creative Commons) media and datasets. They have a section devoted just to movies, and all their content can be downloaded without cost.
• Clicker - The Internet Television guide tells you where you can watch free and paid-for movies online.
• Crackle - If you’re looking for more mainstream movies, here you go. This is Sony’s online movie play. Note: there’s probably some geo-blocking that comes with this. Also, one of our readers has also suggested the UK-based Blinkbox, which seems to offer another platform for more mainstream films. 
• Creative Commons - The folks who gave us the Creative Commons license host a wiki where you can find a good number of freely available films. Handy and worth keeping an eye on. I’d also suggest keeping tabs on CC’s Video blog.
• Documentary Film Network - This site has been archiving documentaries for the past 4 years and serving them free of charge. Among the 181 films, you can find some of the Nixon-Frost interviews and a Che Guevara Biography. 
• Europa Film Treasures - Thanks to Europa Film Treasures, you can spend hours looking back through an archive of European film. Theses films range from “comedy to science fiction, from westerns to animation, from erotic to ethnological movies.” Highly recommended by our readers.
• Film Annex - This site has one of the largest selections of online films for you to watch or download. You can find free classic movies and television shows right here. And you’ll also find at the Film Annex many films from independent filmmakers and directors. The site gives you the ability to download or stream films to your PC, laptop or iPhone. The films are ad-supported.
• FMO - FreeMoviesOnline features a large selection of public domain films.
• Hulu - Unfortunately Hulu limits its programming to a US audience (a policy that really needs to change), but it’s the 800 pound gorilla in the US, and there are some decent films here. You will find some Hulu titles sprinkled in above.
• NFB.ca - NFB.ca is a web site where you can watch films produced by the National Film Board of Canada. It offers access to 100s of documentaries, animated films and trailers. You can also access this collection via a free iPhone app. (p.s. You should also check out our own free iPhone app, which will let you download free audio books, free courses, free language lessons, and other types of intelligent media.) 
• OVGuide - If you’re looking for more free films, you should pay this site a visit. OVGuide is an up-to-date guide to online video, including TV shows, movies, and video games. It offers another way to find free movies online.
• PBS Video - PBS hosts online a new film based on Michael Pollan’s bestseller, Botany of Desire. Other PBS productions are also housed here
• Snag Films - SnagFilms “finds the world’s most compelling documentaries, whether from established heavyweights or first-time filmmakers, and makes them available to a wide audience.” You can watch full-length documentary films for free. Currently includes over 550 films.
• Steven Spielberg Film and Video Archive - This online catalog “provides access to the United States Holocaust Memorial Museum’s Steven Spielberg Film and Video Archive. The Archive serves as a comprehensive informational and archival resource worldwide for moving image materials pertaining to the Holocaust and related aspects of World War II.”
• UbuWeb - Presents dozens of avant-garde films & videos for your viewing pleasure.
• World Cinema Foundation - The WCF, created by Martin Scorsese in 2007, has restored a series of classic international films. You can watch them for free online.
• YouTube Movies - YouTube hosts a series of full-length movies (that are likely geo-restricted).

Sources Used to Create This List:

• Public domain collection of film noir at Archive.org – Boing Boing
• The Best: Movies in the Public Domain – Wired
• Films in the Public Domain – Wikipedia
• Fimoculous list of Hulu Movies
• About.com: Download the Classics
• Salon: The Future is Almost Now

List from Open Culture [http://www.openculture.com/freemoviesonline]