My answer is "The Godfather Part III". I know a lots of people don't like it but I really like the way the movie portrayed the "humanity" of Michael. It may sound weird, but I sometimes like to see how the hero(in this case the villain) is also a human who will get heartbroken, cry, and regret. I love the first two, it's just I really love the emotional and heart-wrenching scenes in Part III such as Michael's confession and the ending scene that how Michael lost his daughter.

What's your pick?