There's many of these and since there's so many as its a popular theme among movie-makers I would like to leave out the bad ones.
Here's the best movies I've seen where the main focus of the story is about making movies or the life of an actor:
The Stunt Man (1980) Peter O'Toole
Realite (2014) Alain Chabat Dir. Quentin Dupieux
The Artist (2011) Dir. Michel Hazanavicius
Le Mepris (1963) Dir. Jean Luc-Goddard
Nobody Knows Anything (2003) Dir. William Tannen
Sunset Blvd. (1950) William Holden, Gloria Swanson
Crocodile Dundee in Los Angeles (2001) Paul Hogan
Hail, Caesar (2016) Josh Brolin, George Clooney
Targets (1968) Boris Karloff
Here's the best movies I've seen where the main focus of the story is about making movies or the life of an actor:
The Stunt Man (1980) Peter O'Toole
Realite (2014) Alain Chabat Dir. Quentin Dupieux
The Artist (2011) Dir. Michel Hazanavicius
Le Mepris (1963) Dir. Jean Luc-Goddard
Nobody Knows Anything (2003) Dir. William Tannen
Sunset Blvd. (1950) William Holden, Gloria Swanson
Crocodile Dundee in Los Angeles (2001) Paul Hogan
Hail, Caesar (2016) Josh Brolin, George Clooney
Targets (1968) Boris Karloff