The best (and worst) Supergirl episodes from all 6 seasons of The CW show
Best and worst Supergirl season 1 episodes
The first season of Supergirl had the difficult task of living up to the hype around Arrow and The Flash. While it aired on CBS, not the CW, the series was still being pitted against its Arrowverse predecessors. Many comic lovers felt the show wasn't necessary and that it was only being done to add a female protagonist to the Arrowverse. With backlash emerging before the show even aired, it was destined to be an uphill battle.
Best: Season 1 Episode 16, "Falling"
Harkening back to Smallville's depiction of red kryptonite as a morality inverter, the episode "Falling" presented audiences with a jarringly different version of Kara Danvers than they were used to. Rather than being the positive, if insecure, symbol of hope she typically was, Kara started putting herself first to a dangerous degree.
This episode was so successful for two key reasons: it gave Kara the chance to stand up for herself, and it showed how hard it is to be a role model. For the first half of the season, Kara let everybody take advantage of her, so fans enjoyed seeing her finally fighting back. While her methods were unnecessarily cruel, the messages largely rang true.
That fact made her downfall that much more effective. Kara struggled with the idea that Astra and Non had been right about Krypton's downfall, and her time with red Kryptonite helped to show her that the ends don't justify the means. A Kryptonian willing to do whatever they want is a dangerous thing. By briefly playing the villain, Kara could finally become the hero she was meant to be.
Worst: Season 1 Episode 3, "Fight or Flight"
It took a little while for Supergirl to find itself, and while the first two episodes are relatively weak, "Fight or Flight" managed to showcase many of the elements comic fans feared when the series was first announced. When Reactron faced off against Supergirl, she repeatedly failed to defeat him until she got outside assistance.
Both in-world and out, Kara Danvers was always going to be compared to Superman. But rather than exploring her own villains from the comics, "Fight or Flight" heavily leaned into the idea that she was a lesser version of Superman, which did not play well. She had to be rescued by Superman in the middle of the episode, and while she eventually defeated Reactron, it didn't keep the episode from making her seem weak.
In addition, the character dynamics hadn't quite solidified yet. The love triangle (quadrangle?) between Winn-Kara-James-Lucy irked viewers who saw it as a sign that Supergirl would just be a teen drama in disguise, and the bonds between platonic characters felt forced. The series frequently argued that Supergirl differed from her cousin because she was able to work on a team, but this episode failed to create compelling team dynamics.