Having seen this film multiple times and read the book it is difficult for me to imagine that the casting director's other options for the lead role were Johnny Depp and Leo DiCaprio. Thank goodness that didn't happen as I can't really imagine anyone other than Bale in the lead.
Despite the fact that Christian Bale has been an actor his entire life, he was relatively unknown in the year 2000. This is why other, bigger stars were being considered. If you have only seen Bale as Batman, you really should get in there and see this "black comedy horror" film where he basically plays the opposite of Batman.
Bale plays Patrick Bateman (that's right, "Bateman"), a very successful Wall Street investor with a few, how do i say this... issues. He is obsessive about most things in his life, doing odd things such as go back to the locker room before working out at the gym to apply more mousse because his hair isn't "just perfect." He obsesses over the fact that one of his coworkers has slightly nicer business cards than he does, and of course he really really like Huey Lewis and the News.
I don't want to be one of those guys that says "the book was so much better!" because I hate those guys. I tend to agree with Jim Gaffigan when he says "You know what i liked about the movie more than the book? No reading."
However, i felt as though the film was a close enough facsimile of the book that even the most dedicated fans would really struggle to find fault with it.
Other than Empire of the Sun, this is the first movie i really recall seeing Bale. It may have been what launched his career and eventually landed him the role as Batman. I thought it was a bit strange to have comic relief in a movie this dark but to be honest, i really works. Oh, the film is quite graphic so don't watch it with the kids around or your parents around if you are a kid.
I can find no fault with this movie and provided you are not turned off by ultra-violence (and there is plenty of it inside American Psycho) I think you will like it