This is not a superhero movie for children. You can bring kids to it, but adults will get much more out of it. Unlike a Disney film, The Dark Knight's morality is not simple black/white, right/wrong. The morality is much more complex and disturbing. It deals with the dark side of free will and human nature; it shows how vengeance affects and corrupts "good" behavior; it reveals the troubling shades of gray of difficult decisions when the "best" choice truly is the lesser of two evils. Where Nicholson played the Joker for laughs in Tim Burton's Batman, Ledger is more disturbing--he plays the Joker as a dramatic villain whose whose violence and victims initially seem psychopathic and randomly chosen, making him a frightening echo of the random violence with which we live in America. And, finally, the suspense of The Dark Knight ends on a surprising, bittersweet, uplifting twist you don't see coming and don't recognize as a possibility until after it happens, not just because of the film's action up to that point, but also because of your own expectations and beliefs about human nature. If you've seen it, you know the moment I mean; and if you haven't, I'm not giving anything away. A truly great film, and a truly great, adult superhero movie.