I was failing to find any of the documentaries by Alanis Obomsawin on Netflix, and was astonished to discover that the full films were available for viewing online by the National Film Board of Canada:

http://www.nfb.ca/explore-by/director/Alanis-Obomsawin/

There look to be some incredible things on this site that haven't seen available anywhere else. Any recommendations for hidden gems in here? Are there parallel sites for other countries?

Glad you found what you were looking for. As for hidden gems, here are some suggestions: http://www.nfb.ca/start/