The 12 worst TV series finales of all time, from 'Seinfeld' to 'Girls'

It's difficult to wrap up a television series, especially shows that have been on for so long that a planned ending isn't really possible anymore.

A good final episode should bring back the themes of the entire show and its season, while tying things up (but not too tight). Often it goes terribly, and even some of the most iconic, well-written shows in television history have terrible finales.

Here, we collected the absolute worst series finales that still make our blood boil.

Here are 12 of the worst series finales in television history, from "Seinfeld" to "Dexter":