If you're confused by the ending...

Rating: 9/10 (2 December 2006)

My take on the ending is that the last killings are so over-the-top there is confusion (intentional) about what is real and what might be in Bateman's head. But it doesn't matter, the underlying theme becomes clear regarding yuppie excess, and the soulless, emptiness and insanity exhibited throughout the movie.
I didn't read the book (and I realize the book is more intense/brutal, etc) but the film gets its point across. What are we really laughing at here? What reflection is presented about American society, class, and bourgeois culture? Seeing how this was set in 1987, during the Reagan years, this film is every bit relevant today, and more so.
My 3¢