Established in 1988, the Library of Congress' National Film Preservation Board selects up to 25 films every year that are ”of enduring importance to American culture." The Doc Channel blog thinks "Paradise Lost" fits the bill:
If there’s any film that fits that description right now, fiction or nonfiction, it’s Joe Berlinger and Bruce Sinofsky‘s Paradise Lost: The Child Murders at Robin Hood Hills. The 1996 documentary has lead to the release of three wrongfully convicted men through its influence and its continuation into two sequels (the third of which was nominated for an Oscar last year). It’s also been a huge inspiration to other filmmakers and legal causes over the years. So, when the 2013 NFR titles are announced this December, I think it should be among the 25.
Interested in helping the effort? You can find the address to e-mail your nomination to the National Film Preservation Board here. The deadline for nominations is September 1.