Your next box set: Dexter

Dexter Morgan is a blood-splatter analyst for Miami police by day and a serial-killer-with-a-conscience by night. Although he takes both jobs seriously, he is also acutely aware of the ridiculousness of his situation, turning up at crime scenes where he is both perpetrator and forensic expert.

Based on the novel Darkly Dreaming Dexter by Jeff Lindsay, and currently in its third series here (on FX), Dexter isn't just clever and original, it's also incredibly funny, which is quite an achievement given its gruesome subject matter. In fact, if it weren't for the serial killer theme, Dexter would have more in common with the likes of Curb Your Enthusiasm's Larry David than Hannibal Lecter. Yes, there's a lot of blood; but you don't ever actually see Dexter killing people - the camera cuts away, allowing us to imagine the rest and still empathise with our protagonist. And, crucially, Dexter observes a strict moral code: he only kills people who really deserve it - generally other murderers whom the police have failed to nail. This policy is known as Harry's Code, after Dexter's foster father, a former policeman who, on realising his son's urges, trained him to use them for good (sort of). It's not quite the boy scouts, but you've got to give the guy points for initiative.

Played with wit and complexity by Michael C Hall (the gay brother David in Six Feet Under), Dexter's extraordinary double life somehow seems believable by just the third episode. And the cat-and-mouse aspect of Dexter's life makes it perfect box-set viewing. Once you've got your head around the concept of a likable sociopath, you can relax and enjoy being in on his big secret. (What's more, as well as being a serial killer, Dexter is a massive commitment-phobe; then there's the fact that his sister - a policewoman, of all things - keeps trying to get him to open up.) It sounds crass and tasteless, and it would be, were it not for the fact that Hall makes Dexter so damn lovable.