Television history is littered with baffling decisions, but few hurt quite like the moment a truly great show gets cancelled. Sometimes the ratings never matched the ambition. Sometimes the network panicked. Sometimes the audience showed up a little too late. Whatever the reason, these series left behind unfinished arcs, devoted fans, and a lingering sense that something special slipped through the cracks. Below are 21 shows that proved brilliance doesn’t always guarantee survival—and why their cancellations still sting.