Neatorama has a post up on 13 Photographs That Changed The World that is an interesting read. Most of the photos are your standard canonical famous photographs, but considering licensing rights, you don't see most of these together in print ever. I do like this entry, about Philippe Halsman's photograph, "DalÃƒÂ Atomicus" (the emphasis is mine)
But before settling on the "Atomicus" we know today, Halsman rejected a number of other concepts for the shot. One was the idea of throwing milk instead of water, but that was abandoned for fear that viewers, fresh from the privations of World War II, would condemn it as a waste of milk. Another involved exploding a cat in order to capture it "in suspension," though that arguably would have been a waste of cats.