Complete Monster: David Allen Griffin was a Serial Killer who stalked women before murdering them with piano wire. After causing the death of Agent Joel Campbell's lover in L.A., he followed him to his new home in Chicago and started killing women there. Griffin sends Campbell photos of his next victims three days before murdering them as part of a game. He successfully murders three young women this way while in Chicago, as well as three police officers during a chase. Near the end of the film, he kidnaps Campbell's therapist and sets the room she's in to explode should the police try to breach it. When Campbell doesn't thank Griffin for "making his life interesting," he attempts to strangle Campbell's therapist, and when the police do end up breaching the room, the explosives go off in their faces. Driven by nothing but the thrill of the kill and the attention that it gets him from Campbell, Griffin cemented himself as a truly psychotic murderer.
Ho Yay: This film has this in spades. All one-sided on David's part towards Joel. David constantly tries to get Joel to realize that they "need each other," and that their cat and mouse games are crucial to both of them.
Mind Game Ship: The more or less canon pairing of David and Joel.
Narm: Oh, several. The slow-motion shot of Reeves dancing headbanger-style to a Rob Zombie song while taunting a victim in an abandoned warehouse for one. And the fact that Joel had to take notes and write down that David was "watching me," as if he wouldn't be able to remember that if he didn't get it down on paper. One reviewer mentioned the scene where Joel's ex-lover was tied to the chair in the burning house, calling his name repeatedly in slow motion, and likened it to a spoof where Cartman from South Park acted the same. Only... they were serious here.
Yaoi Fangirl: In all seriousness, the only people that openly show that they like this film appear to be these. Most (if not all) of the fan videos for this movie are dedications to David x Joel.
The TV series:
Accidental Aesop: Dr. Kaplan's line "You think I can afford to live in a house like that? I'm a retired public school teacher!" is an excellent, though likely unintentional, potshot at the public school system.
