9) Barry Creates Flashpoint – The Flash
Though he’s defeated Zoom, saved the Multiverse and won the heart of his beloved Iris, Barry Allen is still not happy. In the final moments of season 2 of The Flash, the Scarlet Speedster went back in time and rescued his mother from the clutches of the Reverse-Flash. It was a move that promised to completely change the timeline of not only that show but that of the entire shared universe (colloquially known as the Arrowverse).
The Flash proved once again that it was the lead show of The CW’s DC TV universe with this shocking moment, one that went on to have massive ramifications for the next season (including bleeding onto other shows like Arrow and Legends). The following “Flashpoint” arc might not have been quite as groundbreaking as we might have theorized (though, to be fair, we were never really going to get Jeffrey Dean Morgan as a grizzly Batman) but this cliffhanger still stands as the most exciting and mind-blowing end to a season the Arrowverse has ever delivered. Let’s hope we get “Crisis on Infinite Earths” at the end of season 3.