Evolution of Olympic Pictograms

Every Olympics since 1936 has had a series of pictograms (i.e. icons that look like restroom signs) that represents the events. Here are pictograms for the Vancouver games, and here they are for the Beijing Olympics. Some series are distinct while others clearly sucked it up. Designer Steven Heller discusses the evolution of these Olympic pictograms in this video for The New York Times. Which set do you like best?