My Top Twenty TV Science-Fiction Series of All Time

�        1. Star Trek (Original Series) (US, 1966-1969)

�        2. Battlestar Galactica (New Series) (USA/Canada, 2003-now)

�        3. Farscape (Australia/USA, 1999-2003)

�        4. The X-Files (USA/Canada, 1994-2002)

�        5. Dr. Who (Britain, 1963-now)

�        6. Babylon 5 (USA, 1994-1998)

�        7. The Prisoner (Britain, 1967-1968)

�        8. The Twilight Zone (USA, 1959-1964)

�        9. Firefly (USA, 2002)

�        10. Stargate: SG1 (Canada/USA, 1997-2007)

�        11. The Outer Limits (USA, 1963-1965)

�        12. Star Trek: The Next Generation (USA, 1987-1994)

�        13. Torchwood (Britain, 2006-now)

�        14. Sliders (USA/Canada, 1995-2000)

�        15. The Invaders (USA, 1967-1968)

�        16. Blake's 7 (Britain, 1978-1981)

�        17. Fringe (USA/Canada, 2008-2012)

�        18. Space: Above and Beyond (USA, 1995-1996)

�        19. Enterprise (USA, 2001-2005)

�        20. Continuum (Canada, 2012)

      

 The Best of Each Decade

�        Fifties: The Twilight Zone

�        Sixties: Star Trek

�        Seventies: Blake's 7

�        Eighties: Star Trek: The Next Generation

�        Nineties: The X-Files

�        Zeros: Battlestar Galactica

 

Notes: I rated The Twilight Zone fairly low since many of its episodes were more in the mystery, fantasy, or horror genres than science-fiction strictly speaking, which deals with speculation about effects of advanced (or alternative) science and technology on human beings (and the aliens they encounter).