Earths crossover event and was later recruited to be part of The Justice league

Earths crossover event and was later recruited to be part of the Justice League. 

50.) Supergirl (Season 6)

Supergirl Season 6 served as the show's final season, and it featured Kara's final fight against Lex Luthor and the eventual revealing of her secret identity to the rest of the world.

51.) Batwoman (Seasons 2 and 3)

While Batwoman Seasons 2 and 3 are mostly standalone, the main difference is that Kate Kane was replaced by Ryan Wilder as the new Batwoman to protect Gotham City. 

52.) The Flash Season 7

The Flash Season 7 featured the continuation of the Mirrorverse arc, the debut of Bart Allen aka Impulse, and the Godspeed war storyline. 

53.) DC's Legends of Tomorrow Season 6

DC's Legends of Tomorrow Season 6 featured the aftermath of Sara Lance being abducted by aliens and Constantine's departure from the team.

54.) DC's Legends of Tomorrow Season 7

DC's Legends of Tomorrow Season 7 was the final season of the series that featured Booster Gold's arrival, Gideon's human form, and Nate's retirement.

55.) The Flash Season 8

The Flash Season 8 featured the Armageddon crossover event that featured the likes of Atom and Batwoman and the arrival of Despero. This season also introduced Deathstorm and the Negative Speed Force.

56.) The Flash Season 9

The Flash Season 9 served as the Arrowverse's perfect send-off as it featured a plethora of mini crossovers featuring characters from Arrow, Batwoman, and Supergirl. Aside from the crossovers, the final season also featured Iris' pregnancy journey and the return of several iconic Flash villains.