Fidel Castro of Cuba (miss)

If you can devise a harebrained scheme the CIA has not yet used to try to kill Cuban leader Fidel Castro, you might want to send a memo to their Langley headquarters. A 2006 BBC documentary and companion book covered 638 known attempts on Castro's life. The CIA wasn't behind every botched hit on El Comandante, but it is well documented that the agency has hired the Mafia, poisoned seashells, infected a diving suit with fungus and tried to poison his food with drugs to make him appear irrational and insane (some of Fidel's rambling speeches make one wonder if the latter plot hadn't actually worked). According to the book, written by former Castro bodyguard Fabian Escalante, the assassination plots continued until at least 2000, when a former CIA operative was arrested for trying to blow up Castro's podium during a speech in Panama. None have worked, of course, and Castro remains alive—barely.