I'm probably in a minority, here, but I maintain that there has never been a great baseball movie. Don't get me wrong, I loved Moneyball and Bull Durham. I still guffaw at Major League, and even though I like the book better, I don't think I'm capable of turning The Natural off whenever it's on TV.
There are excellent baseball movies. But there isn't anything I'd consider slotting between Godfather II and Bicycle Thieves, if you know what I mean.
Strangely enough, it's a commercial that got me thinking like this. Specifically, the super-neat cinematography. I have no idea what the first great baseball movie would be about. But it would probably come with cool one-take shots like this.