Fight Club
This movie is very well done on so many levels (which is why it's such a cult classic) but there's one big hole in the story. When Tyler Durden shoots himself, he lines the gun up with his cheek. When the gun goes off, it goes out the back of his head. Is this some sort of plot device, or did they just mess up the shots while shooting?
The Sixth Sense
On the surface, The Sixth Sense is a great movie. It's only when you dig a little deeper that makes things confusing. For example, how does Malcome not know that he's dead? He didn't care that people just ignored his existence?