“Dexter” has been on Showtime for six seasons now. That’s longer than the broadcast runs for “Friday Night Lights,” “The Wire,” “Deadwood,” “Twin Peaks,” “Six Feet Under,” and “Battlestar Galactica.” It’s been renewed for two more after this one, which will leap frog it over “The Sopranos,” “Mad Men,” and “The Shield.” Just say that out loud: Eight. Seasons. Of. “Dexter.” And if the next two are anything like the formulaic-to-a-fault one that mercifully finishes on Sunday, may God have mercy on us all. The two Big Bads (a term that means the main villain in a single season) this year, played by Colin Hanks and Edward James Olmos, have been the main problem. Why? Well, read on, as they’re one of the nine worst single-season villains in TV history.
(Spoiler alert, obviously.)








