American football would be Rudy for sure like Yung Wan mentioned because you simply cannot beat that story. Growing up as a kid Varsity Blues was a good one.
In terms of European football and English football,
hands down it would have to be The Damned United. Another great story which I encourage everyone to watch. It is not only based on a true story of a legend (Brian Clough) but it also gives insight into how the English football system operates. If anyone is looking to gain some knowledge on English ball I highly recommend this film.