THE MOST DANGEROUS MAN IN AMERICA is a good documentary about Daniel Ellsberg, who released the top secret "Pentagon Papers" that ultimately led to the end of the Viet Nam war, as well as indirectly leading to Nixon's resignation. It's suprisingly timely with the release of the WikiLeak documents, which parallel the case in that the release of government documents is illegal, yet one could argue that their release is more important than the secrets that are being kept.
It's a good film but it does bog down a bit in the middle. It is completely one-sided with Ellsberg narrating the film, and the re-enactments are a bit on the cheesy side. Yet, it's an important story in American history. Worth watching if you are a fan of history.