My friends and I just finished the most recent season of Dexter, season 6, last night and was a lot better than any of us expected. After the lack of direction nor interesting characters in Season 5, we were mostly turned off from the series. But we picked it up, watched it, and glad we did. :)
I think the reason Season 6 pretty well is that we have an actual fleshed out character as a villain with clear motivation, and actually does plenty of murder throughout the Season. Seasons 1 and 4 did this perfectly and stand as the best two seasons of the show. Seasons 2, 3, and 5 strayed away from this and fall very flat as a consequence.
I think that Season 2 had a pretty tight focus, but the villain was basically Dexter. Unless you count Lyla, but she wasn't a serial killer at all. She's just a crazy bitch, which was more of a manifestation of Dexter's dark side. I think that the suspense of Dexter being caught makes up for the lack of a strong villain, but there still isn't a whole lot of murder going on.
Season 3 is the absolute worse. We do have a serial murderer, but he has no character at all. They never wrote him that way. He's just a dude who skins people. Who is he? I dunno. Jimmy Smitts as the Season's actual villain, but he's not really a serial killer. He's just a controlling asshole, and the whole season focuses on that. Who cares? Get to the killing.
Season 4 felt incredibly fresh after the horror of Season 3. Dexter is out killing again, and his kills actually show his character, and he grows. I wrote about all that while the season first aired: October 20th, 2009. But we have a clear villain, who does a lot of murder. Dexter learns from the clues and tracks him down, while the police are closing in as well. And there's an epic showdown.
With the story they had laid out for Season 5, I think it was doomed for failure. They had to deal with the aftermath of Season 4, while still spinning their own plot. Well, they couldn't just focus on grief the entire season, so they needed to throw a villain in their, too, somehow. And maybe a love plot, too? Whatever... This season focused more on Season 4, rather than itself, and suffered because of it.
With Season 6, they were able to start fresh. A brand new villain, with a clear motive, and their story focused on throughout the season. It was fantastic.
I think they learned from Season 4 a little too much. If you end with a massive cliffhanger, you instantly pull in the audience and make them care far more than the normally would. I'm guessing that Season 5 Episode 1 had the highest amount of ratings of any single Dexter episode thanks to the ending of Season 4. And I expect Season 7 Episode 1 to pull in some serious ratings as well.
Currently, Dexter is signed on through Season 8. I expect them to actually finish off the show at Season 8, but who knows what'll happen.
Also, I expect Season 7 to be somewhat similar to Season 5, but perhaps with a Season 2 edge. It won't be as sappy, or mistake ridden as Season 5 because Dexter isn't some vulnerable lost sheep. But the writers still have to deal with the aftermath. In Season 5, they wrote out almost everything that had to do with Rita, Aster, and Cody, and just moved forward.
I don't think they can ignore Deb, but I wouldn't put it past them to write her as understanding and accepting. Which is the complete opposite of what she would actually do. They have a chance to actually end on a high note, and write an interesting drama filled plot between these two characters, but I fully expect them to fuck it up.
Who knows... In any case, I'm fully invested in this show again thanks to Season 6. :)