Why the Best Movie Characters are Anti-Heroes
Indiana Jones, The Terminator, Dirty Harry, and Travis Bickle. Need I go on?
The Cambridge Online Dictionary defines an Anti-Hero as a central character who does not have traditional heroic qualities and is admired instead for what society generally considers to be a weakness. Unlike the Hero, this character can make wrong moral decisions providing their actions eventually lead them to the right one. The Anti-Hero can be aggressive and opinionated. They can proposition and pilfer. They can pretty much act how they like. Morality is moot, because the Anti-Hero has his own alignment: chaotic good. What is black and white to a Hero, the Anti-Hero sees as grey because as in life its rarely a case of good vs. evil. 
For a perfect example of this archetype, you need look no further than the Man with No Name (Clint Eastwood) from Sergio Leones sprawling Spaghetti Western trilogy. Armed with only his wits, his honour and a red right hand, Blondie roams the west in search of something unknown. He involves himself in the woes of those he meets, always for riches or glory but always with a strong note of compassion guiding his actions. Weve all suffered injustice that we were powerless against and so its easy to admire this legendary Gunslinger; he suffered no injustice he didnt put holes in. In a society in which injustice is, at both a street and conglomerate level, a fixture, the urge to act looms in all of us. Often an Anti-Hero operates outside of the law and in direct accordance with that urge. 
William D-Fens Foster (Michael Douglas), from Joel Schumachers superb urban revenge movie Falling Down, is a prime example of a thoroughly human character that just couldnt take it anymore; criminality, the class system, commercial hyperbole. Despite his obvious psychopathy we cannot vilify D-Fens, in fact quite the opposite; although inflicted by an abundance of societally defined weakness, his actions are tinged with a deep compassion toward a family that he has lost. In short Foster transcends his questionable moral decisions come the credits and takes his place among the admirable. After the senseless murder of his parents Bruce Wayne dedicates his life to the mission and becomes Batman. You know who he is and if you dont, I hope its comfortable under that rock. He has been written about constantly for almost a century and adapted to fit numerous movies, some great and some not so much. Batman is essentially a vigilante, but is halted just short of the mark by his inviolable code of honour; no matter how heinous the offender, he cannot halt a human heartbeat. This is such a perfect balance of stimulation, to both our desire to fight back and the value that we place on human life, and we are able to relate unquestionably as a result of it. 
Heroes appeal to our expectations of perfection; Anti-Heroes appeal to our expectation of ourselves. We do not expect ourselves to attain perfection although we may desire it. The Hero symbolises that desire, with their defined morality and their invulnerability from human weakness. We love a Hero, because we love to escape. Anti-Heroes offer no such escapism. Instead this character attempts to make meaning from the mundane. Those annoyances that we enter the theatre to avoid suddenly pang with emotional resonance and we look upon them in a new light and with renewed vigour. 18th Century philosopher Edmund Burke famously quoted that evil prevails when good men do nothing. Han Solo should be a tool. In life, wouldnt he annoy you? But theres something there that elates us whenever he quips at Luke with a put down, or rattles Leia with a narcissistic come-on. Despite his selfishness and apparent inability to see past his own needs, when evil may prevail Han Solo does something and it is because of this that we cant stay mad at him. 
We can all relate to a character that is motivated by self-interest, as we do ourselves more often than not. Luke is the Hero in Star Wars no doubt and a great one too, but he ascends to the level of a God among men; he is impervious and we cannot truly relate to his humanity. Han Solo experiences our reaction to this Godhood, becoming the point of view through which the audience can tether the plot to their own experiences. Without Han Solo, the original Star Wars Trilogy would not be as iconic as it is, rather it would be just another Sci-Fi movie. The list of phenomenal Anti-Heroes is practically endless. In fact, most of the great iconic figures in Cinema are avatars of this archetype: Indiana Jones, The Terminator, Dirty Harry, and Travis Bickle. Need I go on? For a character to truly affect change in the viewer, they must acknowledge all aspects of the human experience resilience and courage as well as insecurity and cowardice. In a medium that generally encourages style-over-content, Cinema needs these dark representations of humanity in order to maintain relation to its audience. After all, were not Superman.