Movie: Fight Club (1999)
Writer: Chuck Palahniuk (original novel), Jim Uhls (screenplay)
The “split personality” trick has been done to death in both movies and literary fiction, so it takes a really mad genius to make thatgambit a visceral knockout of a reveal. Chuck Palahniuk, fortunately, is just that, and Fight Club, the singularly electric author's cocktail of violence, machismo, and male insecurities, has one of the best multiple identity twists of them all.
One that filmmaker David Fincher, fortunately, did great justice to with his stellar 1999 adaptation. Throughout the story, our unnamed, depressed, and generally messed-up narrator (Edward Norton) slowly gains confidence via an underground fighting circuit, overseen by the super-cool Tyler Durden (Brad Pitt). The brawling ring escalates into a terrorist plot in which Durden threatens to blow up credit card companies' buildings, unless the narrator shoots himself in the face.
Yes, the narrator and Durden are one in the same, with Tyler representing the narrator's manning-up side, so to speak. Talk about beating yourself up over personal inadequacies.