One of the most satisfying things about television is watching a story you've invested in reach a satisfying conclusion. And when that story is a sci-fi narrative that only the creators know to bring to an end, it becomes even more frustrating when the show gets cancelled. Shows like Firefly, Raised by Wolves, and The OA remain among the most controversial cancellations in history. However, one of the worst sci-fi cancellations came at an inopportune time as the show was gearing up for a final season that never saw the light of day. But even with that untimely ending close to four years ago, that show is still a streaming favorite.