The victory of Michael Moore's controversial film Fahrenheit 9/11 at Cannes is further proof of the rise of the cinema documentary.
Michael Moore has blazed a trail for documentary makers
The movie has already been accused of being anti-George Bush propaganda, maliciously scheduled to make its debut in the run-up to the presidential elections.
But there is no doubt millions will watch it to gain exactly what Moore pledges to give them - food for thought.
Moore himself said he aims to make movies that make people "leave the theatre changed". But he is not the only documentary-maker to cause a stir at cinemas worldwide.
BOWLING FOR COLUMBINE (2002)
Moore's greatest success so far, Bowling For Columbine, is a scathing satire of US gun culture. It followed the high school shooting in Colorado in which two teenagers killed 13 of their fellow schoolmates.
The movie won 28 awards, including a special jury prize in Cannes in 2002 and an Academy Award in 2003.
It also proved a huge box office success.
In his acceptance speech at the Oscars, Moore lambasted President Bush over the war on Iraq, which had just started, saying a "fictitious president" elected in "fictitious elections" was sending Americans to war for "fictitious reasons".
Part of the audience cheered him - but he also received loud boos.
FOG OF WAR (2003)
Fog of War, by Errol Morris, is a documentary about former US Secretary of Defence Robert McNamara.
It highlights his role in the firebombing of Tokyo during World War II which killed 100,000 civilians, and in the escalation of the Vietnam war.
The film, put together by editing down more than 20 hours of interviews with McNamara, was praised for managing to portray his personality in a lucid way, showing him as a man whose self confidence remained unshaken.
New York Observer critic Ron Rosenbaum said the director was concerned about how people would perceive his film but added: "I don't think Errol Morris has to worry.
"Nobody who watches this film with any sensitivity to this dynamic of self-deception and self-absolution will see it as a vindication of Mr McNamara's conscience."
CAPTURING THE FRIEDMANS (2003)
Capturing The Friedmans has been hailed both by US and British critics as a compelling and shocking documentary.
It won the grand jury prize at Sundance and was Oscar-nominated for best documentary.
Capturing the Friedmans should have been a documentary on clowns
Andrew Jarecki had started making a documentary about clowns in New York when he discovered that one of them, David Friedman, had a terrible secret.
The focus shifted onto the Friedmans, a middle-class Jewish family destroyed by a scandal which led to the jailing of David's father and brother Jesse after being charged with sexually abusing children.
Jarecki used interviews with family members, police, lawyers and alleged victims as well as video tapes and home movies shot by the family before and during the crisis.
The movie raises lots of questions - but reaches no conclusions about the case. David Friedman says his family is innocent of the charges.
"The movie lifts the lid on this seething cauldron of unspoken, unspeakable shame, takes a good long peep within and then drops the lid again with a clang," the Guardian's Peter Bradshaw said.
TOUCHING THE VOID (2003)
The most successful documentary in UK cinema history is Touching the Void - the gripping story of two climbers fighting for their lives on the Peruvian Andes in 1985.
Psychological drama on the Andes: Touching the Void
Joe Simpson breaks a leg while they are on their way down and is left dangling over an ice crevasse by his climbing partner Simon Yates, who struggles with his conscience before eventually deciding to cut the rope and save himself.
Simpson eventually manages to climb down on his own.
The documentary, which won Kevin McDonald the Bafta for British film of the year, is based on interviews with the two climbers and staged sequences shot on the Andes and Alps.
It has taken £1.68m at British box offices, just ahead of Bowling for Columbine's total.
SUPER SIZE ME (2004)
Super Size Me - a US documentary on a man who eats only McDonald's food for a month and gains 25 pounds in weight - was bound to cause a stir in a country increasingly plagued by obesity.
Director Morgan Spurlock embarked on a tour of fast-food outlets from the east to the west coast, eating three full meals a day.
Spurlock put his health at risk to shoot a documentary on fast food
The effects of this high-fat diet on his body were recorded by a medical team. Spurlock became increasingly depressed and started feeling chest pains, headaches, sugar crashes and heart palpitations.
"Super Size Me packs a lot of good information, witty visual aids and expert testimonials into its fast 96 minutes, and all the bad eating certainly makes for compelling if at times repugnant viewing," wrote the Los Angeles Times' Manohla Dargis.