This really is one of the best sci-fi shows, in my opinion. It's not overly complicated in its science fiction, is creative with the creatures it shows, the characters are memorable and loveable, and the story is very interesting. Series 4 and 5 are a bit of a downgrade, but still very good. For me, the first three series get a 5/5, while Series 4 and 5 get a 4/5.
