Reasons why you should be watching Luther

• It's kind of a procedural detective series, except that, from the very beginning, it's obvious that the show ultimately aims to subvert the genre and its limitations. The cases (gruesome and shocking, all of them) are most interesting when they reveal things about the main characters - what are they willing to do in order to get what they want? How do they justify their acts? How do they relate to each other? 
• Talking about the main characters - there's John Luther (Idris Elba), a Detective Chief Inspector recently returned to his job after undergoing psychological evaluation (because a murderer suffered an unfortunate 'accident' in his presence) - an incredibly intelligent and well-read man who works hard to contain incredible amounts of anger, and is undergoing a gruesome separation from his wife Zoe (Indira Varma). The second main character is Alice Morgan (Ruth Wilson), a "high-functioning sociopath" who grows obsessed with Luther after he investigates the murder of her parents, and eventually manages to affect every aspect of his life. 
• The acting is magnificent. 
• It's a very, very dark show, and not for the faint-hearted (especially the fifth and the sixth, and final, episode of the first season). It doesn't pull any punches. 
• The cinematography is beautiful. Negative space, precise observation of the characters, colours, London... 
• Quotable dialogue on love, justice, the nature of evil, physics and other light-hearted stuff. 
• Brilliant and fitting use of music: the theme song is Massive Attack's Paradise Circus, and the last scene is usually set to a song you'll immediately want to listen to again and again (especially Emiliana Torrini's Gun and a version of Don't Let Me Be Misunderstood by Nina Simone). 
• You will find yourself rooting for and identifying with characters and relationships you never thought you would, and therefore start to question some things you took for granted before.