Writer Annalee Newitz gives an interesting take on The Dark Knight, which is, in my opinion, one of the best superhero flicks of all-time. She basically breaks down ten different messages you can take away from the film. Here's one of them.
2. Sometimes we need to believe in a lie.
Dark Knight ends with Batman taking responsibility for the crimes Harvey Dent committed when he became Two-Face. Batman decides that Gotham City needs a "hero with a face" more than the truth. It needs Harvey Dent to remain pure, and for Batman to become a tarnished hero. Partly, he reasons, the city needs this because vigilante justice is not justice (see 1). But partly it's because people need hope more than truth. Whether or not you agree with his assertion, it makes for an interesting philosophical debate.
Read the rest here (and you haven't seen Dark Knight, run down to your nearest video store and/or gas station and get a copy immediately!)