Basic premise: Is it okay to be a sociopath?
Why it’s the greatest crime procedural (and second best TV show, behind Doctor Who) of all time: Most shows that focus on the supply side of crime rely on anti-heroes. Breaking Bad or the Sopranos are good examples. Yet, Dexter Morgan is not an anti-hero. He is, in a short sentence, Batman if Batman were ever truly broken by the Joker. Dexter, like Batman, is an orphan. His mother is actually killed in front of him as an infant and he is sitting in her blood. The visceral impact of this scene cannot be understated. Maybe Batman would have become a sociopath in such a situation (hell, maybe he is already). In any case, Dexter is an unfeeling, inhuman monster who desperately tries to fit in with society. He likes to kill; he needs to kill, but he does so in such a way that he actually is a genuine hero, in my estimation, perhaps a bigger hero because he has to fight so hard to overcome his impulses.