I've just finished watching all seasons of Dexter - 1 to 7 - back to back, yeah was a marathon and then some.
While my favourite seasons (Ice truck killer, trinity and bay harbour butcher [in that order]) remain the same, the season i expected to be the weakest actually didn't turn out that way (season 3 - the Prada season) and is far from the weakest imo. And a season I thought would feature just after my favourites fell down my personal rating - season 6, Doomsday Killer. Which on the surface seems odd as the subject matter is right up my street, the scenario and twist are great and the tableaus are probably the best visual highlights in the Dexter series.
I've already aired my problems with season 7 so won't bang on about it but one thing I failed to mention has to be noted. While I accept there are narratives we aren't going to see enacted in every season - there's only so much air time etc - in season 7 with Deb's revelation as to who Dexter really is, how on this fucking earth can the subject of Doakes not be covered. Can anyone make a case for it not coming up (it just has to, it can't be washed over as an unseen narrative that happened).
Spoiler
To me it's obvious, there's no way Deb would be able to reconcile Dexter being involved in Doakes' murder - even tho he didn't kill him, she's unlikely to believe that seeing as he is the BHB. We don't even see her saying anything about 'so Doakes wasn't the BHB' - the very first thing surely that would come up when she found the slides in his apartment. Come on, how on earth can that not be the first thing she brings up when Dexter admits he is the BHB? Nope, ridiculous.
Anyway, back to the main point I was going to make having watched every Dexter back to back, is that the weakest two seasons are 6 and 7, in that order. What was very noticeable (having watched seasons 1 to 5) soon as I started watching season 6 onwards was the change in writing. It's much more clipped, corners being cut, lots of unconvincing dialogue in general, which really is a consequence of the clipping etc. Now I don't know if the editing's at fault or the original writing but when you watch them back to back it's actually quite startling at just how foreshortened the dialogue/scenarios are to the point at times of almost being glib, not something I noticed when watching a season unfold slowly at one hour a weak.
I should note that (like most i suspect) once a season has finished I watch it again straight thru after and yet didn't really notice the corners being cut to the degree they are in the last two seasons. It was only watching the whole of Dexter front to back that the change is so readily apparent and to be frank it's pretty piss poor. Sure, I still love Dexter and will be waiting for the final season as much as anyone else but the writing/editing of the scenarios/dialogue have to put right and properly fleshed out as they sure as shit have failed in that respect in recent seasons.