I've often called documentary my favorite kind of film, knowing full well that the label designates less a defined genre than a usefully malleable description. What does a documentary have? An unscripted, nonfictional story; interviews; footage candidly shot — maybe. It may also include scripted, staged, fictional material, and may treat real events in a fictionalized manner or search for the reality in events clouded by fiction. For fine examples of the last, see the works of Errol Morris, four of which — A Brief History of Time on Stephen Hawking (above), November 22, 1963 on JFK, They Were There on IBM, and Werner Herzog Eats His Shoe on, well, subject obvious – you can see right here in our collection of 200 free documentaries online. And speaking of Herzog, the other living filmmaker doing the most to push outward the boundaries of documentary, we have From One Second to the Next, on the dangers of texting while driving, and Portrait Werner Herzog, on his own life and work.

But cinema had the documentary long before it had the likes of Morris and Herzog, and our collection includes a diversity of such pictures from all over the past century. 1958's Ansel Adams: Photographer, for instance, profiles in motion the practice of the man whose work in still imagery anticipated, in many ways, the modern nature documentary. Documentary films have arguably provided the richest means of viewing every kind of creative mind at work, from Alfred Hitchcock (The Men Who Made the Movies: Hitchcock, Dial H for Hitchcock) to James Joyce (The Trials of Ulysses) to Joni Mitchell (Woman of Heart and Mind) to Charles Bukowski (Born Into This). Some of them even came as early entries from not-yet famous directors, including Stanley Kubrick (Day of the Flight, Flying Padre, The Seafarers), Jean-Luc Godard (Operation Concrete), and Kevin Smith (Mae Day: The Crumbling of a Documentary). Nobody can ever say where the documentary form will go next, but watch these 200 and you'll have a pretty fair idea of all the exciting places — geographical, intellectual, personal, and artistic — it's gone already.

See our collection of 200 free documentaries online, part of our larger collection of 635 Free Movies Online.

Colin Marshall hosts and produces Notebook on Cities and Culture and writes essays on cities, language, Asia, and men’s style. He’s at work on a book about Los Angeles, A Los Angeles Primer. Follow him on Twitter at @colinmarshall or on Facebook.