Let's go with this.
1. Hoop Dreams (Steve James, 1994)
2. Gimme Shelter (The Maysles and Charlotte Zwerin, 1970)
3. Welfare (Frederick Wiseman, 1975)
4. Ted Baryluk's Grocery (John Paskievick & Mike Mirus, 1982)
5. Dont Look Back (D. A. Pennebaker, 1967)
6. Paul Tomkowicz: Street-railway Switchman (Roman Kroitor, 1953)
7. Children Underground (Edet Belzberg, 2001)
8. Up Series (Paul Almond and Michael Apted)
9. Roger & Me (Michael Moore, 1989)
10. Stop Making Sense (Jonathan Demme, 1984)
11. Harlan County U.S.A (Barbara Kopple, 1976)
12. Public Housing (Frederick Wiseman, 1997)
13. César's Bark Canoe (Bernard Gosselin, 1971)
14. Hearts and Minds (Peter Davis, 1974)
15. The House Is Black (Forough Farrokhzad, 1962)
16. Woodstock (Michael Wadleigh, 1970)
17. You Are on Indian Land (Mort Ransen, 1969)
18. High School (Frederick Wiseman, 1968)
19. Baseball: A Film by Ken Burns (1994)
20. The Pinochet Case (Patricio Guzmán, 2002)
21. Primary (Robert Drew, 1960)
22. Salesman (The Maysles and Charlotte Zwerin, 1969)
23. Streetwise (Martin Bell, 1984)
24. Capturing the Friedmans (Andrew Jarecki, 2003)
25. American Movie (Chris Smith, 1999)
26. La Lutte/Wrestling (Michel Brault, Marcel Carrière, Claude Fournier and Claude Jutra, 1961)
27. Mad Hot Ballroom (Marilyn Agrelo, 2005)
28. Metallica: Some Kind of Monster (Joe Berlinger and Bruce Sinofsky, 2004)
29. Pour la Suite du Monde (Michel Brault and Pierre Perrault, 1963)
30. The New Mayor (Derek Mazur, Ian Elkin, and Bob Lower, 1980)
31. No Direction Home (Martin Scorsese, 2005)
32. Crisis: Behind a Presidential Commitment (Robert Drew, 1963)
33. Golden Gloves (Gilles Groulx, 1961)
34. Grey Gardens (The Maysles, 1976)
35. Grizzly Man (Werner Herzog, 2005)
36. The Things I Cannot Change (Tanya Ballantyne, 1967)
37. Night And Fog (Alain Resnais, 1955)
38. Paradise Lost (Joe Berlinger and Bruce Sinofsky, 1996)
39. Les Raquetteurs/The Snowshoers (Michel Brault and Gilles Groulx, 1958)
40. Lonely Boy (Wolf Koenig and Roman Kroitor, 1962)
41. Fog of War (Errol Morris, 2003)
42. Ladies and Gentlemen, Mr. Leonard Cohen (Donald Brittain and Don Owen, 1965)
43. The Decline of Western Civilization (Penelope Spheeris, 1981)
44. Anvil! The Story of Anvil (Sacha Gervasi, 2008)
45. Los Angeles Plays Itself (Thom Andersen, 2003)
46. Lake of Fire (Tony Kaye, 2006)
47. Billy Crane Moves Away (Colin Low, 1967)
48. Housing Problems (1935)
49. The Times of Harvey Milk (Rob Epstein, 1984)
50. Frontline: Failure to Protect (Barak Goodman, 2003)