Character Development

(Warning contains generalities)
Most movies do not overly concern themselves with Character development. Sure they have a protagonist who has depth but you also have a villain and generically speaking the villain does not contain a lot of character development. The audience is made to believe that the villain is bad and disrupts the protagonist's life, thus we as audience members are moved to hate or even dislike the villain. This is a very narrow perspective and disallows complexity to enter the story. My personal favorite thing about movies presides within character development. Movies such as The Prestige, directed by Christopher Nolan, and Thor, Directed by Alan Taylor, are two films that illustrate excellent character development.

Although as an audience member you want to hate the villain you are not actually sure who the villain is in The Prestige. You receive an intricate display of character development in both characters and the audience actually receives the opportunity to understand their motives beyond pure greed. You receive the opportunity to see what drove the characters to do such harsh deeds to each other- which does not typically occur in some films.

And then you have Thor.  You desperately want to dislike Loki because you want Thor, the hero, to thrive and Loki seems to always stand in the way... but you simply cannot dislike Loki! He has some really memorable moments in the film. Loki frequently provides comic relief and yet as a villain the audience is moved to understand Loki's motives and because of Loki's excellent character development the audience does not view him as a villain per say but as a misguided and misunderstood man. The audience will actually view him as the underdog when he actually, in retrospect, is the antagonist.
I personally believe that stories that contain a villain/antagonist that has an intricate design of character development is the best kind of story.