I admit to not really watch a lot of documentaries online, but here is a very short very quick list of films that I at least found amazing:

The Act of Killing -

- 2012 - it is both amazing and painful.

Hope Dreams -https://www.youtube.com/watch?v=Ph2Y-epihlk - 1994 - the trailer doesn't do it justice, but it is really hard to do justice to this project. It follows kids from the projects where their only hope is to get out by basketball.

Mr. Death, The Rise and Fall of Fred A. Leuchter -

-full movie (and for some reason it is on an neo-nazi youtube channel)- Errol Morris that got his fame by making a documentary that released a man from prison (The Thin Blue Line) follows a prison execution consultant that became a Holocaust denier. Also his TV series First Person is rather lovely

Life Sentences -

- a bit on the sappy side of direction, but the story is odd enough that it's just has to be that way. An arab and an Israeli get married in the fifties and have two kids. There is a war and the Palestinian territories are conquered. The father (arab) decides to become a terrorist and makes a bomb making factory in the attic. A lot of things happen, but the main protagonist is the son that has had a rough time all in all.

Jodorowsky's Dune -

- The famed cult director tried for years to create his adaptation to the novel. It would have been most likely an odd and difficult experience, but stunning beyond belief (if to go on his most famous films Holy Mountain and El Topo). The project failed, but had an amazing impact on other film makers.

And just because it is a documentary that changed how they are and will be- Lanzmann's Shoah.

- (part 1) It is a nine hour long film about the Holocaust and survivors. It is difficult and painful. The one thing that this documentary is unique is the lack of archival footage of camps or the dead. Lanzmann offers a stand against the image within a film.