You'd think, if told there's an 84-minute documentary on the ending of Mass Effect 3, that it'd be the result of some crazed fans, crackpots spending most of that time exclaiming breathlessly into a cheap microphone. You would also be wrong, because this thing is great.
It's basically a very in-depth examination of the various "Indoctrination Theories", all of them based on the belief that the ending of Mass Effect 3 sucked so much because it didn't really happen. And it didn't really happen because Shepard had been "indoctrinated" (ie taken over) by the Reapers.
The whole thing is worryingly comprehensive, and while it still doesn't make me a believer (many of the points are more likely the result from lazy/rushed development than some grand conspiracy), it's still fascinating to see how such a thing can result in such a thing.
The Indoctrination Theory - A Documentary