YoutubeThe largest video site, but you should be careful for the legality of videos and potentially offensive comments. There is an ‘Education' category, where videos are uploaded by colleges or universities. For example, Stanford University provides access to whole courses filmed in their classrooms.
VimeoSelf-claimed as "a respectful community of creative people", it seems there are more users who are aware of copyright rules. Unlike Youtube, you can download videos in their compressed format, as long as the creator has given the permission. It can be a useful site for media, film and creative arts teachers and students as it has High Definition, high quality art videos.
iTunes UUniversities such as Oxford and Harvard are uploading videos of lectures and course materials. All videos should be watched using iTunes installed on your computer.
Internet Archive - Moving Image ArchiveMany videos are Creative Commons-licensed, free to download. It ranges from classic full-length films, to daily alternative news broadcasts, to cartoons and concerts.
Archive-ItWeb archiving service for collecting and accessing cultural heritage on the web. The content includes videos and websites that no longer exist on the current Web, such as performance art videos at biennials.
EuropeanaProvides historical images/sounds/videos contributed by 1500 European institutions. You can filter your search by media type (sound, video, etc.).
Open ImagesStarted by the Netherlands Institute for Sound and Vision, it offers interesting videos such as historical footage from the late 19th century. Provided under the Creative Commons licensing model, the content can be downloaded and remixed into new works including Wekipedia.
ARTtubeA collective video channel for art and design in the Netherlands and Belgium. It includes interviews with reputable artists and designers, and curators who talk about museum's master pieces.
Search Your Film ArchivesYou can search multiple film archives across the UK. Videos include footage of British people traveling Africa and Asia. Use Advanced Search to find "Only records with video online" if you would like to view videos on your desktop.
Sistine Chapel 3D ViewNot technically "video", but this provides high quality Sistine Chapel views that you can explore in a virtual reality setting. The zoom-in feature allows you to look at Michelangelo's Last Judgment and the ceiling frescoes very closely. (Courtesy of Villanova University of Pennsylvania for its contribution)
Historical Film Resources
Travel Film ArchiveA collection of travelogues and educational and industrial films that show the world the way it was between 1900 and 1970.
Rhizome ArtBaseOne of the oldest online archives of digital art containing projects from artists all over the world.
UbuWebA resource for the avant-garde, ethnopoetics, and outsider arts. The film index is available by artist/provider's name.
Video Data Bank (VDB)Created by a not-for-profit organization located at the School of the Art Institute of Chicago, this is a leading resource in the United States for video by and about contemporary artists.
Videoart.netIt serves as an international network for video art and experimental films.