6.Dexter
This series is about a blood spatter analyst named Dexter who lives in Miami Florida, however Dexter has a secret life, during his time off Dexter is a serial killer. He kills strictly by his step-father Harry’s code. Which told Dexter how to not get caught, and also to only kill other killers. Working for the Miami Police Department while living as a criminal makes for an interesting double life, and a very interesting series.