4. American Psycho
Unlike many of the other entries on this list, American Psycho is a film that achieves its question of madness through form and purpose as opposed to random details that accumulate incidentally. Did Patrick Bateman really go on his gory murder spree, or was it all in his head, the blood-soaked daydreams of a morally adrift yuppie who's world view has gradually enclosed him within a snow globe of homicidal madness? Ellis' book walked this line carefully, but suggested that, no matter, Bateman's was a voice not to be trusted to logical reality. The film, doing its best to emulate that ambiguity, has a harder time because of the visceral and concrete sequences of Bateman's slaughter. As a serial killer, he's of course expected by the audience to be a bit off his rocker, but incidents like his return to the apartment to find it clear and clean of the aftermath of his activities do alert us to the ephemeral nature of his 'reality'. In fact, almost every incident that occurs is subsequently rebuffed or dismissed by some real-world element that either refuses to see his depravity or cannot reflect it because it belongs completely to his mind. It almost doesn't matter whether Bateman has killed or not, because at some level, the entire film has been a morbid fantasy in his brain, tweaked and turned and allowed to run its fearsome course because this high-class guy seems so unlike the murdering type. When the lawyer laughs off his confession, he also mentions that he's seen one of Bateman's victims just recently. In the book, I suspect this was something Ellis was actively hinting at--that the wall between real killer and an unhealthy fantasy life of imaginary violence and destruction can be very thin indeed.