I have just finished the first season (only 12 episodes long). Its simply the most well written and acted show I have ever seen.
PLOT: Based on Jeff Lindsay's novel "Darkly Dreaming Dexter," this new crime thriller tells the story of a strange man named Dexter Morgan. Once an abused and abandoned child, Dexter is now a successful forensics pathologist...but lurking just beneath his charismatic personality is a terrible truth. Dexter has corralled his innate homicidal urges into a closely guarded second career: He hunts down and brutally murders those vicious criminals who have managed to avoid the clutches of the law.
Word of caution, this show is very graphic and has some pretty disturbing scenes. If you dont like blood, dont watch this.