OK Everyone, its time to create a documentary thread.
It may have already been done, but i haven't been around here long enough to know, so i'm just going to go for it.
This thread came about due to discussion about a terrible World War doc.
IMHO the best documentaries are pretty timeless. Sure our knowledge of facts and details changes over time (science documentaries are particularly affected) but all the doc needs to do is provide a thorough and complete look at what the opinion of the time is.
I'm going to divide this into categories and add suggestions to the OP to try and provide a complete reference so people can find high quality docs easily.
I will *try* to watch at least one documentary of a series before i add it to the OP for quality control. If i am unable to do this i will base its inclusion on reviews from trusted sources.
History
The First World War (BBC) (2003)
Very comprehensive and factual. Shows a range of opinions and views from the time.
Science
Cosmos: A Personal Voyage (1980) (PBS)
^^ This is IMHO the greatest series of documentaries ever made. Carl Sagan was such a great speaker. RIP
Wonders of Life (2013) (BBC)
Just a clip, but the full episode are available online. A controversial choice, Cox being well known as a Sagan wannabe, but there's some truly great science in there.
Psychology/Sociology
5 Steps to Tyranny
Psychology documentary. Are you capable of unjust/harmful actions? You might not think so...
Politics
The Fog of War (2003)
An interview with McNamara. Not a series but an astoundingly honest interview.
Religion
The Power of Myth (1985) (PBS)
A massive series of interviews with mythologist and academic in the field of comparative religion, Joseph Campbell.
Let it be known that in religion, all documentaries are going to come down to opinion, and this is but one of many.
It is known
Media
Manufacturing Consent
A short documentary explaining the work of Noam Chomsky, the lefty academic who contributed a huge amount to the study of the media and how it works from an outsiders point of view.
Miscellaneous
Connections with James Burke
Massive series of docs which choose a start point and then generally go on massive tangents to see where it leads. James Burke is a genius for making this.
More categories will be added as required.