I never considered Breaking Bad heavy???? It was a comedy to start with. (granted a black one, but still ) Then it got a bit more serious later on. But even later, they were doing some comedic stuff.
True Detective was pretty heavy all the way. (I really enjoyed that one.)
I actually watch The Walking Dead for the moral dilemmas they fall into and how the character react/interact (and I like apocalyptic shows/movies). If you are watching it for the zombies, you are missing about 75% of the show. (I realize a lot of people are into zombies which is fine, I'm not. I don't watch zombie movies, other than "Zombieland" because it was a black comedy.....and Emma Stone was in it.)
I agree though, that there are a lot of shows out there now trying to do the season premier, midseason finale, midseason premier and season finale.