2. Dexter
The Showtime series starring a serial killer started out as a critically acclaimed show that caught the attention of many viewers. Dexter Morgan was a clever and likable antihero who had the ability to cause viewers to question their own morals. The first season showed serious promise, but the second season started to show signs of a struggling plot. The end of the second season presented several problems for Dexter, as the bodies he had dumped into the ocean began to resurface, forcing him to come up with a cover story.
The Season 2 finale let Dexter (Michael C. Hall) off the hook a little too easy. But viewers were still left with some hope that Season 3 would return better than ever. Interest in the show began to dwindle in the third and fourth seasons; meanwhile, it continued on for another four years. Grantland says the show’s fifth, sixth, and eighth seasons were incompetent, while its seventh season offered a pretty repetitious plot.