Saw 'em both. Raging Bull was a better
film, but Field of Dreams was a better
sports movie. I have the utmost respect and awe for RB (and DeNiro specifically, he was incredible), but watching FOD for the first time when I was 12, with my dad, was a completely different experience than watching Raging Bull. What I got from Raging Bull, I've also gotten from the Godfather, Citizen Kane, Bridge on the River Kwai, and most other great films I've seen. What I got from FOD, I've never gotten anywhere else.
edit: Having said all that, in a perfect world there'd only be a vote or two separating them.