One of the great TV series of all time. To achieve this it has to be original so you don't think the scripts have been written by a computer programming that cuts and pastes the "best" bits out of other series or just rehashes something that's already been done but long enough ago that the key audience won't have seen the original. So it's original by creating a lead character that's a serial killer but he has to be a hero as well or it's going to be a villain in a slasher series. So he's given the **code** which only allows him to kill the really bad guys. He's very intelligent but how's he going to get the information he needs so he can be sure he's targeting a real bad guy who deserves what's coming to him or her? So even though he smart enough to become a top doctor he chooses to become a forensic scientist and work for the police. Access to police records and forensic evidence that allows him to make a correct choice for his next victim. With the excellent scripts you have the basis for a hit series. When you add a set of very good actors who are asked to play superb characters it all falls into place. Intricate plots and twists and turns in every story keeps your attention akin to a book that's a great page turner. It's always a good idea to quit when you're on top but I was disappointed that Dexter had to end but at least it didn't suffer a slow and lingering death with main characters bailing as the end becomes clearer and clearer. If you check the discussions you'll see a number of people who watched all seasons of the show in a binge approach of viewing all episodes one after the other. To give people the incentive to do that it's got to be an exceptional TV show.
My wife and I absolutely loved this show. Just watch it if you enjoy very dark, suspenseful stuff with good characters and almost a casual light attitude even though the whole thing is so dark and gory. I just need to warn you, stop watching after season 5. I loved season 5 but after that my wife and I were devastated by the last seasons. We think it went down the wrong path and ruined the show for us. Go through season 5 and then just read the endings of the next seasons on some blog or something and forget about watching it. This will make your memories of the show stay great. Trust me, don't watch those final seasons.
One of my favorite TV series of all-time, possibly one of the best ever made for a time. The acting, writing, and plot are all so well-done and unique. The only problem is the unreasonable expectations from the first seasons make people hyper-critical of the latter ones. In my opinion, the only "bad" season was 8, and a lot of that has to do with the manner in which the writers end the story (no real finality). If you have yet to watch Dexter, I envy you as I wish I could go back 15 years and watch the first episodes again. I can't recommend this show enough, it's the series that made me love television.