The only reason I felt the The Sixth Sense was worth watching was because of the carefully orchestrated twist at the end. I thought it took too long to develop that ending, and I have the same problem with Unbreakable. But again, the ending (which is even more clever than the one in The Sixth Sense) is what makes this film worth watching.
I consider comic books to be one of the greatest forms of literature. I'm not just referring to those that feature fairly mainstream and traditional heroes like Superman, Spiderman, or Spawn, but also the Disney comic books (especially featuring Uncle Scrooge, which can easily be considered "art") and the European ones such as Asterix, Tintin, and Lucky Luke. Perhaps the most compelling use of the comic book art form to make a point is Art Speigelman's Maus books.
The importance of comics would appear to be the primary message in Unbreakable at the outset. David Dunne (Bruce Willis) is extremely fortunate: he has gone through life (almost) without a single injury. When he escapes a train wreck that kills all the passengers except him, he comes under the scrutiny of Elijah Price (Samuel Jackson) a comic book aficionado who believes that comics simply are an historical account of a real struggle between super heroes and super villains. Elijah believes that David is possessed with psychic and indestructible powers and that he must use it to combat evil. Skeptical at first, David slowly begins to believe Elijah, who they call Mr. Glass because he has osteogenesis imperfecta or brittle bone disease (for people who are interested in scientific accuracy, the correct ordering of the intensity of the disease (in increasing order) is type I, IV, III, and II).
As I walked out of the film, I was impressed enough with the cleverness of the ending that I forgot all about the slow pacing. The special effects are minimal and the character development (of both David and Elijah) is done well. There's a hilarious, almost surreal, scene in the film where David's son Jeremy (Spencer Treat Clark, who also in Arlington Road, a surprise-twist-at-end film) tries to test the theory that his dad is a super hero by pointing a gun at him and threatening to shoot. There's also another amusing scene involving David lifting weights.
I was left unsatisfied with the treatment of comic books in the film. As a huge comic book fan, it really bothered me that comic books were reduced to such a simplistic view, but yet their importance was being touted. However, again, the ending which really turns the film from a typical story about heroes and villains to a comic book style story about super heroes and super villains, is what makes this narrow vision of comic books excusable.
The surprise ending sets itself up for a sequel in the grandest of all comic book traditions, after the arch-villain is sent away to a criminal asylum. As epitomised by villains like the Green Goblin or The Joker, comic book villains never really go away.