I love Documentaries and I've been seeing more and more of them mentioned in the Rate The Last Movie You Saw thread so I thought I'd start a discussion topic on them. If it doesn't take off, we can merge this with the General Movie Discussion thread.
I have more than a few favorite documentaries, so I'll list a bunch of them here to give you an idea :
B3773R Living Through Circuitry
The Last Waltz
Brothers Keeper
Hearts of Darkness: A Filmmaker's Apocalypse
Bowling For Columbine
Capturing the Friedmans
Dogtown and Z-Boys
Murderball
Project Greenlight
Edgeplay : A Film About The Runaways
Found On Everest : detectives on the roof of the world
Game Over: Kasparov and The Machine
Grizzly Man
Stoked: The Rise And Fall Of Gator
Metallica : Some Kind Of Monster
Red Light Go : Alley Cat Racing In New York City
Paradise Lost : The Child Murders At Robin Hood Hills
Paradise Lost 2: Revelations
Super Size Me
Party Monster: The Shockumentary
The Search For Robert Johnson
Spellbound
Trembling Before G-d
The Celluloid Closet
What Happened To KEROUAC
Basically, the ones listed above are in my personal DVD collection.
Quick mention here - for me, personally, the films of Michael Moore tend to be more an Editorial than a Documentary, but I've included them... because they do document his editorializing.
So ... what are you favorite documentaries and why?