We all watched a lot of TV shows or series in our life. But sometimes, what used to be a great story, with our favorite characters and settings, can be destroyed by the ending. It can let us down, or do a unwanted plot twist that ruins everything.
It's not easy to finish a series with everything done right, but sometimes they just throw it at the garbage.
I remember "Two and a Half Men" for example. Eight great seasons, but then everything went downhill and the final episode was very, very poor. But I think this isn't the best example, since the show had a couple of bad seasons before that.
What about you? Do you have other examples?