6. Black Lightning
Long before The CW's cancellation spree of summer 2022 kickstarted the end of the Arrowverse, it randomly decided to prematurely end Black Lightning with its fourth season. This unfortunately saddled an already-crowded season that lost one of its main cast members with the impossible task of wrapping up the whole series. Bear in mind that this is the season that toyed with Black Lightning's own death and that the show was fresh off its introduction into the Arrowverse.
The show always worked better as its own entity, but there was a lot of excitement about Crisis On Infinite Earths' creative choice to house the show on Earth-Prime along with its Arrowverse counterparts, but its premature ending prevented it from ever making the most of that. And thus, its final season was once again a contained story.
There were highs and lows throughout Black Lightning's final season, especially in regards to the aforementioned storyline involving the departure of Jennifer Pierce, but it did manage to focus on some of the hard-hitting themes that separated the show from its more gimmicky counterparts. The Painkiller backdoor pilot episode was also a delight that teased a new potential future for one of the show's most underrated characters (although it unfortunately wasn't picked up).
There were more mixed feelings in the series finale itself, with fans torn on how it wrapped up the Pierces' storyline. While it was a serviceable conclusion to the show, it didn't quite manage to give Black Lightning the excellent send-off it would have been capable of in a more definitive final season.