Worst: The Extra Arcs
Don't get us wrong, we were ecstatic that NBC allowed a series that probably cost more money than it earned the opportuntity to reach almost 100 episodes. But during the show's third season, and then again for the fourth, the network ordered an inital 13 episodes for the season only to unexpectedly extend the order to full-season length midway through. More Chuck! Sounds like a dream come true for us fans, right?
Well, it would've been except that showrunners Chris Fedak and Josh Scwhartz approached each of the initial 13 as if that was all they were going to get, and planned accordingly. The first half of both seasons are tightly plotted, fully-formed arcs with a beginning, and decidedly epic and satisfying ending (in case it wound up being the end).
Schwartz and Fedak were right to approach them that way; most of the blame is with NBC. The episodes that followed play like an unnecessary sequel to a great movie, featuring underwhelming stand-alones and extensions of the overall season plot that inevitably felt sloppy and rushed.