Rank #1: Apollo 8
Picture: The Earth as seen from the Moon, photographed by the Apollo 8 crew (NASA)
Rank #2: The Yangtze Incident
Photo: The HMS Amethyst (F116) arrives in Hong Kong after it's epic escape down the Yangtse. (Photo Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images)
Rank #3: Strikers In Saris
(Photo: Jayaben Desai, leader of the Grunwick strike committee holding placard 1977 Credit: Getty images)
Rank #4: The Death of Hitler
Photo: Hitler and some of his officers. Credit: Getty Images.
Rank #5: Hitler's Architect
Picture: Albert Speer standing at the gate of his house near Heidelberg in December 1979. (Credit: Roger George Clark)
Rank #6: The First CIA Coup in Latin America
Photo: Jacobo Arbenz and his wife speaking with a group of French reporters in Paris in 1955. Credit: Getty Images
Rank #7: Hitler's stolen children
Photo: Ingrid Von Oelhafen aged about two. Courtesy of Ingrid Von Oelhafen.
Rank #8: Englandspiel: The Deadly WW2 Spy Game
Photo: Haub Lauwers identity card when he joined the Dutch army in exile.
Rank #9: D-Day
Photo: The photo titled "The Jaws of Death" shows a landing craft disembarking US troops on Omaha beach, 6th June 1944 ( Robert Sargent / US COAST GUARD)
Rank #10: Criminals in the community
Rank #11: Vikings in North America
Photo: Replicas of Norse houses from 1000 years ago at L'Anse aux Meadows. (LightRocket/Getty Images)
Rank #12: Chinese restaurant syndrome
It was linked to the man-made flavour enhancer monosodium glutamate or MSG – but it was also part of wider attitudes towards Chinese restaurants at the time.
Lucy Burns speaks to restaurateurs Philip Chiang and Ed Schoenfeld about their memories of what became known as 'Chinese restaurant syndrome'.
Photo credit: Plates of Chinese food (Dean Conger/Corbis via Getty Images)
Rank #13: Hitler's League Of German Girls
Photo: Eva Sternheim-Peters at home in Berlin (Credit: Stefan Thissen)
Rank #14: WW1: Revolution in Germany
Photo: Revolutionaries in a truck with machine guns in front of the Brandenburg Gate in Berlin, November 1918 (Photo by Culture Club/Getty Images)
Rank #15: Under the North Pole
Photo: The USS Nautilus arriving in the UK. Copyright: BBC
Rank #16: The Story Behind The Man Who Shot JFK
Photo: Lee Harvey Oswald on November 22,1963, during a press conference after his arrest in Dallas. Credit: AFP/Getty Images.
Rank #17: The fall of Singapore
Picture: British soldiers surrender to Japanese forces in Singapore in 1942. (Credit: Mondadori Portfolio via Getty Image)
Rank #18: UFO Sightings: The Rendlesham Forest Incident
(Photo: Computer illustration of UFOs - Unidentified Flying Objects)
Rank #19: The Killing of the Russian Tsar
(Photo: Nicholas II, Tsar and his family. From left to right - Olga, Maria,Tsar Nicholas II,Tsarina Alexandra, Anastasia, Tsarevitch Alexei and Tatiana. Credit: Press Association