The 3rd Man for mystery, although whether that is American is debatable. Also, I didn't like it that much (I think I saw a really bad print), but it seems to have a good reputation. Breaking Away has to count as a sports film. At least my dad, who is a cycling fanatic, always counts it as his favorite sports movie. I think that should be there for sure, along with Raging Bull, Rocky, Bull Durham, Chariots of Fire (or was that wholly British?) and Hoosiers. Hoop Dreams, obviously, unless documentaries will be separate at a later year like you conjecture. I like When We Were Kings a lot too, if documentaries within a genre are eligible. Million Dollar Baby, possibly? I wasn't a huge fan, but it did win the Oscar. I've heard Pride of the Yankees is good but I've never seen that. The Hustler would have to be top 10 if pool is a sport. There have to be some good car racing movies, don't there? But I'm drawing a blank. The really interesting thing would be if they counted Gladiator movies or Kung-Fu movies as sports films. Gladiating was a sport at the time, and martial arts (in the form of judo) are in the olympics. If they count those, I think we can count on Karate Kid being there, though I haven't seen that in over 20 years and I don't remember liking it, so I don't think it would be on my personal list.