My roommate and I just watched the tail end of American Psycho. It's hard to categorize the movie - it's not really a horror movie, although that's probably the closest it comes to a genre fit, and it's certainly not a thriller or a traditional action movie. It's not an action movie at all, in fact. The point is that the pleasure of watching the movie is that the main character, played by Christian Bale, is so likable. Watching the movie, kind of a Catcher in the Rye for the 1980s, I identify with his hatred of all the phonies of the world and his desire to kill them. What appear to be his lived actions mirror our own fantasies on a more annoying day. Like Holden Caulfield, Patrick Bateman is an anti-hero we can't help but like.
The same guilty pleasure applies to many action movies. While the hero is an important part, it's really the villain that makes the movie. James Bond can't function without Ernst Blofeld. The Die Hard movies all had their efficient, professional and yet fatally flawed terrorists. The Rock has Ed Harris fighting the good fight and threatening to wipe out San Francisco. What makes these movies work is that we all have a part that wants the villain to succeed. The villain's success is, of course, detrimental to thousands, even millions of innocent lives, which is unacceptable to a moral world view. Our desire threatens our view of ourselves as moral people.
The tension in an action movie is finally resolved by the hero's defeat of the villain, saving vast numbers of innocent lives. More importantly, he saves us from the illicit desire to see the villain succeed. In American Pyscho, the resolution of the movie is partly a disappointment and partly a relief for this reason.