Throught the history of movies, there have been a wide range of boxing related movies or documentaries.

Five of the best are:

Cinderella Man
About James J Braddock

Fat City
An excellent film about a down and out boxer

Raging Bull
First class film about middleweight Jake LaMotta

Ring Of Fire The Emile Griffith Story
Excellent documentary with real fight scenes.
The final scene with Griffith meeting
Benny Kid Paret's son was an emotional ending.

Somebody Up There Likes
Excellent story about Rocky Graziano winning
the middleweight title from Tony Zale