The Hustler, League of Their Own, and Enter the Dragon were easy choices for me. I want to vote for a 4th though.
I am torn between Tin Cup and Rocky III. I am tempted to go for Rocky III if only because it launched Hulk Hogan to fame and that was responsible for the huge boom in wrestling in the 80s... a fairly significant cultural event (and perhaps a sporting event too). It certainly has more lasting impact than Tin Cup. Rocky III also gave us Mr. T. I am not sure if I can forgive that.
--Jason "what a choice!!" Evans