If the anime was never completed, Then you're in luck. You can continue the story by reading the completed manga. This list has basically the same rules as a couple of my other ones, includes anime originally based on a manga, no...
A comprehensive list of every Anime I have taken to completion (or feel I have seen enough) and my thoughts on each. Order was chosen based on personal enjoyment and feelings on the series in question.
Astronauts, space travel, interstellar war, aliens, and more!
I'm always looking for good anime and I happened to stumble upon these 50 series that are basically unknown. I felt the need to share with others. I recommend each of them. Some more than others, but they're all worth the try...