I actually really enjoyed Season 8, despite much of the fanbase disagreeing. I think the season was a perfect wrap up of Dexter's Miami life, and Season 8 did a great job with that.
The season starting off with Debra having PTSD from killing Laguerta I thought was accurate to her character, and also real life examples of it. Throughout the season, there was a slow improvement, a good pace, to Debra and Dexter becoming back to normal.
Evelyn Vogel was also a very interesting character in how she helped create Harry's code. She was integral to the story, and as Dexter even said toward the end: If she hadn't helped Dexter and Debra, they probably wouldn't have found each other again. I think Vogel's death made sense in the long run, as it truly showed how psychotic Daniel is, which only served to drive Dexter to kill him more.
The farewell from Miami Metro also was very sweet, especially when Batista made a speech about Dexter at the memorial for Evelyn.
There was a sort of full circle moment in this season. Actually, a few. The biggest one is how from Season 1 to Season 8, we see Dexter, the man who thought he had no feelings, fall in love, start a family, grieve in his own way, and find love again, until his final sacrifice.
Another was Dexter finally letting go of his Dark Passenger and letting Miami Metro take Daniel into custody, granted Dexter did kill him later, but it was still a big step.
His grieving over Deb's death was also a character growth moment, as since he was always the person who looked out for her, he felt he needed to do so one last time. Since he wasn't able to live with the guilt and the grief, he tried to sacrifice himself.
There are many more plot points I enjoyed, but I would be here all day if I listed them all.
Anyway, this is just my opinion. I'm sure some won't agree with it, and that's okay. Just remain civil. :)
Onto New Blood next.