Two good comedies about making Hollywood movies:
Under the Rainbow
A comedy about the making of The Wizard of Oz
No, it isn’t, at all. While I won’t complain about the tangents, I was thinking of movies where one or more of the characters has such an interest in a real movie that really already exists in the outside world that it makes up a major part of the plot of the movie. The main character’s obsession with Fargo in Kumiko the Treasure Hunter. Everyone’s obsession with The Graduate in Rumor Has It. (In the most closely matching examples, the movie would have scenes of the character watching real footage from the real movie as happened multiple times in Kumiko.) To go on a bit of a tangent, George’s obsession with Breakfast At Tiffanys on an episode of Seinfeld and the My Dinner With Andre episode of Community come close. So far none of the movies mentioned fit my intentions, but that may be because there aren’t many examples to mention. I know I’m not thinking of any–Fanboys with The Phantom Menace comes close, but without TPM even being out yet in the movie.
5-25-77 is all about a guy who obsesses over Star Wars.
There was also Fanboys, about nerds who want to get an early screening of The Phantom Menace.
Not even “Son of Rambow”? I thought that was pretty close, with the two main characters being focused on the movie “First Blood”.
… containing a puppet show.
If we’re going to allow plays, *Kiss Me Kate *is a musical film about people making a stage musical based on a Shakespeare play. Events on and off stage are parallel.
Heck, throw in* Free Enterprise* about a couple of Star Trek uber fans who get to meet and hang out with William Shatner.
You know it’s utter fiction because one of them, despite being marginally employed, is shown (sometimes in flashback) as having dated/bedded at least five absurdly hot women. Granted, the movie is set in Los Angeles, which acts as a hottie gravity well, but geez…
Louis Malle’s Vanya on 42nd Street is about a group of real actors who came together to produce an spartan and non-commercial production of Checkov’s Uncle Vanya which actually becomes a production of the play; that is, it starts with the players gossiping and discussing the characters and then just turns into them playing the roles without any transition. If was the result of Malle pseudo-documenting the actual development of the play by the actors over a period of months prior to the filming.
Stranger
Okay, maybe a couple of them–I was re-skimming all the replies before posting. Play It Again, Sam sounds like a fit, too.
Living In Oblivion (1995).
Steve Buscemi is an no-budget independent filmmaker in New York. If you’ve ever worked on an indie film, you’ll totally get it.
I love Peter Dinklages’s rant. 
(NB: F-bomb dropped near the end of the one-minute clip.)
An unsung masterpiece just for the barfight scene 
Ah, my apologies for misunderstanding. So not movies about *making *movies, but about regular people watching real movies. You’re right, that’s a much smaller universe.
The only example fitting your criteria I can think of right now has already been mentioned: Play it Again, Sam. But even that uses only a brief (but quintessential) clip from *Casablanca *at the beginning, and a famous quote spoken by Woody’s character at the end. The rest of *PIAS *deals more with the archetypal Bogart character, and only references Casablanca sparingly.
One of the reasons there are so few examples may be that the makers of the meta-film will have to get permission if they want to include actual clips from the real film, which is probably not easily obtained, unless the studio and/or principals of both are the same, and maybe not even then. Even merely using quotations or referring to characters or scenes could provoke the threat of litigation if the producers of the earlier film wanted to get persnickety about it.
Not really in line with o.p.’s request of a movie centered around a real movie but entertaining nonetheless, Galaxy Quest is about a bunch of washed up actors from the eponymous cancelled television show (which itself is a clear fictionalization of Star Trek) who are abducted by aliens who received transmissions of the original show and interpreted them as “historical documents” and then recreated all of the imagined technologies and cultural artifacts (much to the horror of Alan Rickman, who despises the role and what it did to his stage career, as well as the meal of “Kep-Mok blood ticks” he is served) as well as the plot complications written into the show such as the Omega-13 device, the countdown destruct timer that always stops at 1, and the “chompers” which serve no apparent function and which Sigourney Weaver’s character scorns as “bad writing”. The actrs are abducted by the Thermians, who are essentially alien fanboys of the show, and forced to deal with a very real threat from an evil alien. The movie ends with the show being revived with the original cast including “Guy” (Sam Rockwell’s dispensible securoty officer who is killed off in an episode with only one screamed line of dialogue) and “Jane Doe” who is actually one of the Thermians in human form.
Man, that movie was so good in so many ways even aside from the metatextualism and satire.
Stranger
Another (pretty weak) example of what I’m thinking about is Raymond’s obsession with The People’s Court in Rainman, which does slightly shape the plot. TV series and not movie, but same general idea
There’s another episode of Seinfeld (actually a two-parter), The Cadillac, where George is obsessed with Marisa Tomei and is caught by Susan watching My Cousin Vinny and Only You.
Blair Witch 2 is set in a universe where Blair Witch 1 is a movie that the main characters are all fans of.
Sunset Blvd.* (1950) - 'Nuff said.
*Hollywood Story *(1951) - Hollywood Story (1951) - IMDb
“During the 1950s Hollywood, an independent producer unwisely opens an old can of worms when he decides to make a movie about the 1930s unsolved murder of a famous silent-film director.” Features many clips from real movies and is inspired by the 1922 murder of director William Desmond Taylor.
The Spirit of the Beehive (1973) - The Spirit of the Beehive (1973) - IMDb
“In Castilla around 1940, a traveling movie theatre brings James Whale’s black and white film classic “Frankenstein” (1931) to a small village. Two young girls, Isabel and Ana, are subsequently determined to find the monster themselves.”
The Legend of Billie Jean (1985) - The Legend of Billie Jean (1985) - IMDb
Teenager watches Jean Seberg in St. Joan (1957), cuts her hair like Seberg and takes inspiration to fight an injustice.
Well, then youve gotta mention Being There for Chance’s obsession with TV in general.
mc