The problem with the whole Shaymalan twist thing is that you go into the movie expecting one and then get to work trying to figure it out throughout the whole movie. This actually ruins the whole experience because you instantly get 3-4 theories together while watching which makes you miss the point behind the movie because you are looking for evidence the whole time. After that the movie can only be one of two things, something one claims they obviously saw coming the entire time, or something that was not good enough because theory #4 was better.
In this I think the 6th Sense was the only real big success because the audience did not go into it expecting a surprise at all. They just watched a film and was amazed at the end of what happened.