4. Luther (BBC, 2010 - 2013)
Possiblly the most amoral detective of his generation, Luther's (Idris Elba) methods are unorthodox to say the least. He sees no issue in dangling suspects over the side of buildings if the end result is justice. Because that's what Luther lives for - he just loves justice. Can't get enough of it. A man with a seemingly endless supply of grey clothing and red ties, Luther isn't an enigma - rather he is a caricature of one. He's troubled, with the requisite messy personal life and artfully scruffy lifestyle. He's also violent, and I struggle to see how he has avoided the Police Complaints Commission for so long*. We like to believe he's on our side, that he would be a good man to have in our corner. But that's only because he would be truly terrifying as an adversary. Luther's curve ball, so to speak; what transformed it from an engaging show to a great one, was the presence of Alice (Ruth Wilson), who is a far more credible enigma than the grey-coated detective. But what really sets the drama apart is the relationship between the two of them. It's sort of like a BBC-friendly, inverted version of Silence of the Lambs, only Ruth (as far as we know) doesn't eat her victims. *Incidentally a warped version of the PCC does catch up with Luther in the third series. Unfortunately the man running the investigation is just as corrupt as Luther himself.