I am watching through the show (I'm now on season 9, episode 6) and I must say that season 8 is my favorite in terms of score. Its melodic and even has themes!! I also really liked the plot (I know most fans dont like it, lol).
I never knew that the This Is Not Happening theme returned for the season finale AND that it was included in the box set!! (I only listen to the score as I finish the episodes their from)
EDIT: And the theme also appears again in season 9, episode 10! Amazing! Hope they include some cues from this episode (Providence)