"Lost" (2004-2010)

If "Twin Peaks" was the start of fans endlessly puzzling over a TV show to figure out its mysteries, "Lost" may be its greatest descend ent in that area. Over six seasons, the show's plane crash survivors, trapped on an island, tried to figure out what they were doing there and what they would do with each other. In addition to inspiring a million fan theories, the strong character development kept viewers returning for more.