The show The Walking Dead. I enjoyed the first season. It wasn't amazing, but it had good pacing, emphasized the characters, and showed some zombies. Then the second season came and I just lost interest.
But there was that scene on Hershel's farm (when things were actually happening) where the barn had been opened and the survivors were knocking zombie heads off one by one. And then the little girl came out, and Shane didn't know what to do. Rick, having been challenged for leadership the whole time, got to step forward and show people that being leader didn't mean you could just boss people around. It meant making hard choices. Having to put the girl down emphasized the sacrifices Rick continued to make. And then the season just sort of petered off, Shane didn't get much character development, etc.