I used to be obsessed with the assassination of John F. Kennedy. From the age of 10 until my mid-teens (when I finally realized the fallacious nature of most, if not all, conspiracy theories), I formulated different theories as often as I changed socks. On any given day, I was as likely to be convinced that Fidel Castro was behind the plot to kill Kennedy as I was to believe that it was an elaborate plan by the Mafia. JFK's assassination is unusual in the realm of conspiracy theories, in that everyone is a suspect, and it is impossible to rule anyone out. Unlike other popular conspiracies (from the moon landing to 9/11), there is no iron-clad explanation that holds up under intense scrutiny.
Oliver Stone's "JFK" takes the uncertainty surrounding Kennedy's murder and exploits it to masterful effect. Back when the film was first released in 1991, it brewed up a storm of controversy because audiences simply didn't know how to react to such a brazenly unfocused examination of such a confusing subject, and it was believed that Stone was attempting to offer plausible solutions to the many mysteries surrounding that terrible day. Although I concede the possibility that Stone has indeed been elected mayor of Crazytown, I think it's more likely that he intended his film to serve as a reflection of a national mood rather than a definitive statement on its subject.