I watched it for the first time today and was mesmerized by the clever animation and the wonderful dialog between characters voiced by Dizzy Gillespie and George Matthews. The film dates to 1962, highlighting not only Cold War fears but race relations as well, as we see a black and white construction worker having what seems to be an easy rapport between each other in a hole of a New York construction site. The film is as apt today as it was then.
The Hole won an Oscar back in '62, which makes it surprising that it took so long to be recognized, but this project was only begun in 1989 so I guess they have a lot of catching up to do, especially if only inducting 25 films per year. What makes the list compelling is that you can nominate films yourself. You don't have to be an academy member or film critic. Your choice has to be at least 10 years old and have cultural, historic or aesthetic value. If you can't think of one off the top of your head, here is a long list of films the NFR considers worthy of suggestion.