One thing I think the movie deserves credit for is how philosophically sophisticated it is. Most Hollywood films are really quite lazy in this area.
Nolan really took his time to try to work out the logic of his worlds, and also think through how these things impact the characters on a human level. The film raises interesting issues, not only about appearances vs. reality (the standard Matrix stuff) and knowledge, but also about personal identity (who am I? on what grounds would I say that I'm the same person I was before now?), and the reasons we have for believing what we do, as well as the reasons we have for being motivated to do what we do.