Field of Dreams - If Frank Capra had made a baseball movie, this is the one he'd have done. Bull Durham - The complete and polar opposite of Field of Dreams. FoD is ethereal; Bull Durham is gritty. FoD is fantasy; Bull Durham is real life: about the guy who wasn't good enough. Rocky - About the guy who finds out that he's better than he thought he was. Raging Bull - The real story of a man who was a much better athlete than human being. Happy Gilmore - I wouldn't want to spend 1 minute around a real person with that personality, but the movie makes me laugh every time. Rudy - This is a sports movie for all the rest of us, who didn't have the size or the skill. Alas, most of us aren't possessed of his effort either. Rudy has a Balboa-esque heart. The Longest Yard (not the remake) - Redemption, acceptance, and..... Ah, hell. I still really laugh when Burt Reynolds keeps throwing the ball and hitting Bogdanski in the nuts. Bad News Bears (again, not the horrid remake) - Guilty pleasure movie. Matthau played a great drunk/slob. Major League - THIS MOVIE HAS TIGER BLOOD!
And, separately, a couple of spectacular documentaries:
Hoop Dreams - One of the greatest films ever made, sports or not. Ken Burns' Baseball - I still re-watch all 18+ hours of Burns' masterpiece every or two. Not as famous, but I urge all to watch all of his films, including "The Unforgivable Blackness of Jack Johnson".