Best Movie Ever centers on the production, reception, and legacy of the 2001 film Josie and the Pussycats, which starred Rachael Leigh Cook, Tara Reid, and Rosario Dawson as the titular band. Based on characters created by Archie Comics, Josie and the Pussycats was a box office disappointment for MGM and Universal, who produced and distributed the movie, but has gone on to become a cult classic in the years since.

Best Movie Ever is the product of dozens of hours of interviews with members of the movie's cast and crew, as well as industry analysts, comic book creators, and the fans who helped keep the movie alive after the filmmakers had been told it was "dead on arrival."

Released in 2001, Josie and the Pussycats earned less than $20 million on a budget that has been reported in the $30 to $40 million range. Its soundtrack, which featured Kay Hanley of Letters to Cleo singing as Josie, went gold, and eventually got a 2017 vinyl reissue from Mondo, who also hosted a special fan screening, concert, and Q&A to go with it. From YouTubers and bloggers to Buzzfeed and the Los Angeles Times, Josie and the Pussycats is getting a critical reappraisal now that would have been difficult to imagine in 2001.