The series finale is not just the end of a season. The final episode of any show--from short-lived single seasons to long-running, much-loved TV classics--is a chance for writers and showrunners to deliver something truly memorable and satisfying, giving audiences a payoff that will have them thinking about those final minutes for long after. From M*A*S*H and Cheers to Breaking Bad and The Americans, some of the greatest, most powerful episodes of any TV shows have been series finales.

But of course, there are those series finales that get it very wrong. In some cases, the bad end can be predicted for some time. Shows that have gone on way too long, often shedding viewers, cast members, and showrunners until they are finally put out of their misery by the network. In these cases, terrible final episodes were just the last in a long time of bad episodes, with seemingly little interest from everyone involved in making it good.

There are also bad series finales to shows that were still good, that totally fail to deliver what fans were expecting. Sometimes there are dramatic and bizarre narrative decisions that leave fans scratching their heads, and others times just a reluctant shrug that says “will that do?” And of course, some shows ended terribly simply due to sudden cancelation, with no opportunity for writers and producers to wrap things up properly. But in every case, these were not the endings that fans had hoped for, and are now remembered as truly terrible conclusions to often great shows. So here's our rankings of the worst ever...