David Holzman's Diary (1967)

Jim McBride's satire on cinema verite filmmaking may not be the first mockumentary -- for example, Peter Watkins' little-seen The War Game, a fake news doc about a nuclear attack on Britain, was produced two years before. Still, Diary was a remarkable formal breakthrough, and a key work of American independent cinema. In the movie, the unemployed and possibly Vietnam-bound cinephile David (L.M. Kit Carson) attempts to chronicle virtually every aspect of his life, but his endeavor is met with disdain (and sometimes violence) from the people around him. Shot over five days on a minuscule budget, McBride's film was a goof on the hyper-seriousness of the documentary process, and laid the groundwork for movies that blurred the line between real life and fiction. "Where most independent productions are founded on self-righteous claims of truth and honesty, McBride's film wittily observes that Hollywood has no corner on illusionism," wrote Dave Kehr of the Chicago Reader.

Real Life (1979)

At this point, few viewers are likely to believe that reality television isn't manipulated in some way, be it by heavy editing, music cues, or intentional omissions. Albert Brooks' directorial debut Real Life satirized such conventions before they became commonplace. Brooks stars as an intrusive, egocentric filmmaker who decides to film the daily doings of an average American family. However, rather than allowing for journalistic detachment, he arrogantly attempts to control his subjects' lives in order to make a more compelling movie. Made in the wake of PBS's pioneering reality show An American Family, Real Life deftly demonstrates that reality is hard to come by when the cameras are rolling. Larry Carroll of Countingdown.com called it "a great, underrated, lost gem of a film that accurately predicted and lampooned reality television long before it ever came to be."

Cannibal Holocaust (1980)

By their nature, mockumentaries make us uneasy; the dividing line between fact and fiction is part of the genre's appeal. However, Cannibal Holocaust did more than disquiet audiences - its director, Ruggero Deodato, was arrested in Italy on charges he'd made a snuff film. Cannibal Holocaust is the story of four documentarians who go missing while filming indigenous peoples in the rainforests of South America. When an anthropologist finds their footage, he learns the distressing, depraved nature of their deaths. Despite the grisly realism of the murders depicted in the film, no humans were actually killed during the making of Cannibal Holocaust (a fact that allowed Deodato to be released from jail), but a number of animals were slaughtered on camera, which led the movie to be banned in several countries. "The effect is now familiar, but back then it was incredibly shocking, as most viewers believed every word of it," wrote Christopher Null of Filmcritic.com.

Warning: NSFW on any level.

Zelig (1983)

Woody Allen's strange tale of a "human chameleon" is unique in his body of work; it's also technically stunning. Allen stars as the title character, a 1930s-era man with the ability to transform himself to fit in with the people around him. Zelig's story is told in the form of a contemporary documentary, with "academics" and "historians" providing insight into the life and fame of the protagonist. Made 11 years before Forrest Gump, Zelig utilized bluescreen technology to integrate Allen with archive footage; he shows up alongside such noteworthy figures as Charlie Chaplin, Babe Ruth, and Al Capone. Zelig is a "hilarious Woody Allen vehicle, a mockumentary with special effects ahead of its time," wrote Steve Crum of Dispatch-Tribune Newspapers.

This Is Spinal Tap (1984)

This is Spinal Tap marks a turning point for the mockumentary form; what was once fodder for cinematic experimenting became a genre unto itself. Rob Reiner's hilarious faux-chronicle of the decline of a clueless metal band was so spot on in its details that many failed to realize it wasn't actually a doc; rock legends like Steven Tyler and Eddie Van Halen barely batted an eyelash at Spinal Tap's misfortunes, and some close to Reiner asked him why he didn't choose to follow a better-known band. In a modern-day example of life imitating art, the primary members of Tap -- Christopher Guest, Michael McKean, and Harry Shearer -- actually cut records and played stadiums, and the movie became a back-of-the-bus staple for touring bands. The film's influence on the mock-doc is easy to spot; the Tap trio has gone on to create such fake flicks as Waiting for Guffman and Best in Show, while the hip hop-skewering Fear of a Black Hat mines similar satirical territory. "There had been countless documentary spoofs before This Is Spinal Tap, but this inspired put-on was the first to actually capture the texture and style of real documentary," wrote Sean Axmaker of Seanax.com.