Which sci-fi show has the best theme tune?
Considering instrumentals alone, I would suggest it's the season 5 intro to Babylon 5.
I think Star Trek Voyager has the best opening theme.
There's one other that had a great song but the show itself only last 3 seasons in the early 80's. The show was called The Greatest American Hero, and it would be classified as a comedy/drama. A group of aliens give a suit to a high school teacher which gives him super human powers. The song was called Believe It or Not and it was so great it made the top 40 countdown. It was sung by a singer called Joey Scarbury.
Doctor Who - the most innovative, frightening, mysterious and alien-sounding of all TV themes, let alone the Sci-Fi genre. I write, of course, about the original arrangement realised in 1963 by the brilliant Delia Derbyshire of the BBC Radiophonic Workshop, and include the embellished versions of her masterpiece which were used up until 1980. After that, various, arguably inferior, synthesiser arrangements were employed until the demise of the classic series in 1989; of these, Peter Howell's (1980–1985) was the most respectable.
Science Fiction Theatre (1955). Theme song by Ray Bloch. After 50 years, when I heard it on late-night TV, it instantly took me back to 1955! Bloch was the orchestra conductor/arranger for The Ed Sullivan Show, and the orchestra conductor on the Jackie Gleason Show.
My opinion Babylon 5.
I liked the small narration at the beginning. First by Commander Sinclair, then by Captain Sheridan and then the last 2 season by the whole cast.
Sometimes it was ominous.
The late Andreas Katsulas was very good narrator. Especially at the season 3 cliff hanger finale.
My person choice is a true "blast from the past" when I was 9. It was composed by John Williams (credited as Johnny Williams) and only lasted one season on ABC. It was The Time Tunnel and if you have never seen it, watch the pilot. The entire series is available on Hulu.