Rocky for me here.
Now before any comments are made about the subsequent Rocky films, lets remember that those aren't being voted for. This is Rocky in a vacuum, where it is one of the best sports films as well as one of the best underdog films ever made too.
Stallone famously hammered out the first draft of the script in 3 days and stuck to his guns to make sure that he would be able to play the role himself. It cost the film $1 million dollars as the producers were willing to provide a $2 million budget if a big name could be attached for the leading role. The film then made a total $225 million worldwide gross, a phenomenal feat.
Eye of the Tiger is forever paired with the Rocky franchise but the original theme, Gonna Fly Now is one of the most uplifting and inspirational pieces of music that is constantly used at sports arenas to get the crowd pumped up.
It has to be Rocky.