This is the full version of the 1977 documentary that aired on ABC shortly after Star Wars: A New Hope premiered in theaters, and it's pretty amazing if you're a hardcore fan of the series.
This is how the world saw the film before it was a legacy, before the sequels and the piles of merchandising and video games. George Lucas looks impossibly young, and it's fascinating to hear him talk about his inspirations for the film and to see what went into the movie's practical effects.
It's also fun to see the fashions and haircuts of the fans as they line up in front of the movie theater. This was a relic from a completely different time, not weighed down by decades of expectation and hype. It's not likely to contain any new information, and was included in the 2011 Blu-ray release of the original trilogy, but it's still a fun way to get ready to re-watch the films.