Of those mentioned, The Longest Yard. I think that Varsity Blues is a better H.S. Football movie than Friday Night Lights, but that's just me. I'm easily swayed by Ali Larter, especially when she's wearing a whip cream bikini.
People always seem to leave out Paper Lion, All the Right Moves, Knute Rockne - All American and Wildcats when discussing football movies.
Jim Thorpe - All American too