Another classic series ending

Whilst scanning YouTube I came across the famous ending of another television series - Blake's 7. The series was unusual in having two final ever episodes - the story goes that the fourth season was unexpectedly greenlighted during transmission of the climax of the third! The third season ended with the ship Liberator destroyed, the villain Servalan seemingly dead, missing hero Blake reported as dead and the remains of the seven trapped on a hostile planet. It was't the most spectacular of finishes and I doubt it would be remembered beyond fans of the show itself. But the fourth season turned everything on its head, delivering a climax that is very hard to beat:

Of course there have been attempts to continue the story, including the rather dull novel Afterlife, as well as endless development hell for a "further adventures of Avon" special mini-series. But the above stands as the memorable ending to all memorable endings.