Here's a blast from the past: the 1977 Australian documentary UFOs Are Here! has been placed on Archive.org as a free download (in multiple formats). Yes, that's 33 years ago folks:
This UFO documentary film was produced in 1977... Sadly, the master copies of this film and the two which followed it have been lost to the ravages of time. Only one VHS copy of it survived; so Australia's Channel 9 gave us permission to convert it to digital video in an effort to preserve it as an archive for the use of posterity.
The documentary is notable for featuring a number of the 'big' UFO names: Jacques Vallee, Allen Hynek, Kenneth Arnold, Stanton Friedman, Betty Hill and Ray Palmer. It also features a young Steven Spielberg, around the time of his seminal Close Encounters of the Third Kind.
I've embedded the video below - if you'd rather download a copy, head to Archive.org. Note that there is an extended introduction by writer Stan Deyo, so if you want to dive straight into the documentary then you'll need to skip ahead to about the 10 minute mark of the video:
Thanks to dp1974 for the heads-up.