Turn off the TV and Read: Dexter

This crime thriller follows Dexter Morgan. Dexter is a forensic blood spatter expert for the Miami Dade Police Department. He is the main support for his sister. He has a steady girlfriend, with two kids who adore him. He also has an active "night life". Based on a code instilled in him by his foster father, Harry, he hunts down people who have escaped justice and makes sure they don't get away with a crime again. (x)

 I Hunt Killers by Barry Lyga

What if the world's worst serial killer...was your dad?

Jasper "Jazz" Dent is a likable teenager. A charmer, one might say. But he's also the son of the world's most infamous serial killer, and for Dear Old Dad, Take Your Son to Work Day was year-round. Jazz has witnessed crime scenes the way cops wish they could—from the criminal's point of view. And now bodies are piling up in Lobo's Nod. In an effort to clear his name, Jazz joins the police in a hunt for a new serial killer. But Jazz has a secret—could he be more like his father than anyone knows?

 The Silence of the Lambs by Thomas Harris

A serial murderer known only by a grotesquely apt nickname-Buffalo Bill-is stalking women. He has a purpose, but no one can fathom it, for the bodies are discovered in different states. Clarice Starling, a young trainee at the FBI Academy, is surprised to be summoned by Jack Crawford, chief of the Bureau's Behavioral Science section. Her assignment: to interview Dr. Hannibal Lecter-Hannibal the Cannibal-who is kept under close watch in the Baltimore State Hospital for the Criminally Insane.

Dr. Lecter is a former psychiatrist with a grisly history, unusual tastes, and an intense curiosity about the darker corners of the mind. His intimate understanding of the killer and of Clarice herself form the core of The Silence of the Lambs-and ingenious, masterfully written book and an unforgettable classic of suspense fiction.

 Heartsick by Chelsea Cain

Damaged Portland detective Archie Sheridan spent ten years tracking Gretchen Lowell, a beautiful serial killer, but in the end she was the one who caught him. Two years ago, Gretchen kidnapped Archie and tortured him for ten days, but instead of killing him, she mysteriously decided to let him go. She turned herself in, and now Gretchen has been locked away for the rest of her life, while Archie is in a prison of another kind---addicted to pain pills, unable to return to his old life, powerless to get those ten horrific days off his mind. Archie's a different person, his estranged wife says, and he knows she's right. He continues to visit Gretchen in prison once a week, saying that only he can get her to confess as to the whereabouts of more of her victims, but even he knows the truth---he can't stay away. When another killer begins snatching teenage girls off the streets of Portland, Archie has to pull himself together enough to lead the new task force investigating the murders. A hungry young newspaper reporter, Susan Ward, begins profiling Archie and the investigation, which sparks a deadly game between Archie, Susan, the new killer, and even Gretchen. They need to catch a killer, and maybe somehow then Archie can free himself from Gretchen, once and for all.

And of course the obvious one being the series the show was based off starting with

 Darkly Dreaming Dexter by Jeff Lindsay

Meet Dexter Morgan, a polite wolf in sheep's clothing. He's handsome and charming, but something in his past has made him abide by a different set of rules. He's a serial killer whose one golden rule makes him immensely likeable: he only kills bad people. And his job as a blood splatter expert for the Miami police department puts him in the perfect position to identify his victims. But when a series of brutal murders bearing a striking similarity to his own style start turning up, Dexter is caught between being flattered and being frightened -- of himself or some other fiend. 

How about the season finale, I was shocked at the ending.