Some that haven't been mentioned:
I think Dogtown and Z-Boys is a great documentary on the emergence of modern skateboarding.
(Don't watch Lords of Dogtown, the theatrical version).
Stacy Peralta also did "Riding Giants", a documentary on big wave surfing.
A film I liked about the corruption in college basketball is Blue Chips. A film I liked about lyncanthropy in high school basketball is Teen Wolf.
Any Given Sunday had Pacino acting a little nuts but I kind of liked it in terms of exploring some of the modern issues of professional football. Jerry Maguire had both Cruise and Cuba Gooding acting a little nuts but I liked the emphasis on the sports agent part of the game. The Replacements has Neo saying "Pain heals, chicks dig scars, glory lasts forever." Neo was also in a terrible DUI court-mandated baseball coach movie called Hardball.
Then there's the endless parade of college/highschool football movies like Rudy, Friday Night Lights, the Program, Varsity Blues.
There's also the penal sports movies like Victory (or Escape to Victory) (WWII soccer with Pele, Bobby Moore and Sylvester Stallone), the Longest Yard (prison football with Burt Reynolds), the Longest Yard again (prison football with Adam Sandler), and Mean Machine (remake of Longest Yard but with Vinnie Jones playing prison soccer).
Of course, that leads to penal boxing movies like Undisputed. And other boxing movies like the Fighter, Diggstown, the Hurricane, Southpaw, Million Dollar Baby, Ali, and Cinderella Man.
Going through this exercise has led me to believe that there are a lot of sports movies.