Rocky III
For me, this is the second best movie in the series but you could make a compelling argument for it being better than rocky 4. For me this isn't as well-rounded as rocky 4 but I like Rocky 3's plot slightly better and I think Clubber Lang is a better villain than Drago. But, it falls short in other aspects. Still one of the best sports movies of all time. 4.5 stars for me.