Discovery Education - Subscription-based.
History.com - Video and audio offered by The History Channel
Internet Archive is a non-profit digital library offering free universal access to books, movies & music, as well as 150 billion archived web pages.
neoK12 - video resources for grades K through 12.
San Diego Zoo/Wild Animal Park Videos - Great videos about the animals at the S.D. Zoo, Wild Animal Park, and more.
SchoolTube - education-based video sharing website similar to, and based on, YouTube, but not blocked by school districts.
SqoolTube Videos - Educational Videos for Pre K- Grade 8 (hundreds of videos!)
TeacherTube - video sharing website similar to, and based on, YouTube.
The Open Video Project - video clips from a variety of sources, especially various video programs obtained from U.S. government agencies such as the U.S. Records and Archives Administration and NASA.