I know most of them, a very good list:

So far I have as S Tier:

The Act of Killing
Apollo 11
Planet Earth 1/2
The Beatles Get Back
Searching for Sugar Man
Free Solo (?)
Citizenfour (?)

Anything else?

Did not make the list, but great:
Herzog stuff
Blue Planet
Our Planet Behind the Scenes
The Last Dance
The Vietnam War
My Octopus Teacher
Meru
Man on Wire
Jiro Dreams of Sushi
Honeyland
The Century of the Self
The Elephant Queen
Magnus
Exit Though the Gift Shop

I suggest adding Robert Flaherty's Louisiana Story, and also that Strauss-sympathetic movie about fans of The Shining, room something or other it is called?  What else?