The Ten Best Science Fiction Series ever aired

[Athene]

Which science fiction series are in your top ten?

Mine are:

1. Star Trek TOS
2. Battlestar Galactica : The Original Series
3. Dr. Who
4. Space 1999
5. Lost in Space
6. Six Million Dollar Man
7. Bionic Woman
8. X-Files
9. Time Tunnel
10. Wonder Woman

It's a close tie for me with Star Trek TOS and TOS BSG. ;)

[gmd3d]

Mine would be
1. Star Trek TOS
2. Battlestar Galactica : The Original Series
3. Babylon 5
4. Space 1999
5. Blake's 7
6. Six Million Dollar Man
7. Voyage to the Bottom of the Sea
8. Red Dwarf
9. Time Tunnel
10. The Greatest American Hero

[Damocles]

Mine would be
1. Babylon 5
2. Battlestar Galactica : The Original Series
3. Star Trek: TOS
4. Hitchhiker's Guide
5. Doctor Who
6. Lost In Space
7. Voyage to the Bottom of the Sea
8. Red Dwarf
9. Time Tunnel
10. Twilight Zone

[Aphrodite]

Ten?

I'll give you what I got:
1) Battlestar Galactica (the original)
2) Babylon 5
3) Firefly
4) Farscape
5) Star Trek DS9
6) Stargate SG-1
7) Battlestar Galactica (RDM)
8) Star Trek TNG

That's it so far...

[Westy]

1: BSG (the real one, of course)
2: Firefly
3: Bablyon 5
4: Star Trek: Enterprise
5: Star Trek: TOS
6: Space 1999
7: Space: Above and Beyond
8: Lost
9: X Files
10: Dr. Who (the newest incarnation of it)

Not sure about the exact order of 5 to 10, but the 1st 4 are definately in the correct order.

[Kester Pelagius]

Ten BEST series? That's a tough one, especially if you grade a series based on it's entire run. Many started strong (Stargate SG-1, Buck Rogers) but ended weak (Stargate SG-1, Buck Rogers).

My top picks in no particular order:

Firefly - Never had a chance to go downhill.
Farscape - Best Buck Rogers/Flash Gordon inspired series ever.
Battlestar Galactica TOS - Non-syndicated version.
Dr. Who - Especially the Tom Baker years.
Red Dwarf - Best UK SF farce series I've seen.
Banner/Crest of the Stars - It's an really good anime series.
Star Trek TOS - I can still watch reruns of this.
The Outer Limits - Best of the SF themed anthology series, IMO.
Babylon 5 - It had it's up and downs but overall very good.
LEXX - Most original SF series in a while.

I'd probably come up with a different list tomorrow. So I'll include a few honorable mentions as well:

Sliders
Jericho
Eureka - A surprisingly silly fun series.
Crusade - Possibly the best spin-off series ever. I loved the episode that did the X-Files homage.