This is a condemnation of course, but also praise, because my message is not simply that the ending was poor, but that the show rose so high that it was able to fall so very far. (There are, of course, major spoilers in this essay.) Other SF shows have ended very badly, to be sure. Sadly, I’m hard pressed to think of a TV SF series that had a truly great ending.
In such situations, a poor ending is to be expected.
To make things worse, TV shows are usually ended when the show is in the middle of a decline.
That’s the sort of ending you might find in a great book or movie, the ending that caps the work perfectly, which solidifies things in a cohesive whole.
Great endings will sometimes finally make sense out of everything, or reveal a surprise that, in retrospect, should have been obvious all along.
I’m convinced that many of the world’s best endings came about when the writer actually worked out the ending first, then then wrote a story leading to that ending.
There have been endings that were better than the show.
Star Trek: Voyager sunk to dreadful depths in the middle of its run, and its mediocre ending was thus a step up.
Among good SF/Fantasy shows, Quantum Leap, Buffy and the Prisoner stand out as having had decent endings.
Babylon 5’s endings (plural) were good but, just as I praise Battlestar Galactica (BSG) by saying its ending sucked, Babylon 5’s endings were not up to the high quality of the show.
(What is commonly believed to be B5’s original planned ending, written before the show began, might well have made the grade.) To understand the fall of BSG, one must examine it both in terms of more general goals for good SF, and the stated goals of the head writer and executive producer, Ronald D. The ending failed by both my standards (which you may or may not care about) but also his.