Top 20 Greatest Sci-Fi TV Series

Battlestar Galactica or The Expanse?

Had Firefly made the movie Serenity a bit more epic, we made have got more Firefly seasons.

Star Trek TNG was by far the best science fiction show ever on tv. In fact much of it was not fiction but treatment of current social, ecological and political issues. Nothing else even comes close. Want to learn about the possible effects of climate change and the subsequent social reaction? Watch The Inner Light. Communication? Darmok. Human humility? Q Who? The list is endless.

You missed Babylon5 in the #1 slot.

Firefly, ST:DS9, ST:Lower Decks, BSG (remake) & Dr. Who (classic and newer).

Quantum Leap was my favorite, but you left out The Strain.

Agents of SHEILD should be up there, very underrated sci fi show

My favorite sci fi shows are Star Trek the original series, Star Trek the Next Generation, and Star Trek Picard.

Number 1 shoulda been Voyager 😢

The expanse is phenomenal they shouldn’t have ended the show at least not with so many questions left unanswered

My favorites include "The Orville" for it's unusually intelligent science-fiction plot lines and humor. Also "Raumpatrouille" which was not shown in America but had incredibly impressive visuals for a TV show.

Notable absenses: Black Mirror, Travellers, Star Trek Strange New Worlds and Farscape!

In my opinion putting anything above BattleStar Galactica 2009 is ABSOLUTE BLASPHEMY, it is THE G.O.A.T.

I was about to pee all over this list because of the low placement of shows like Quantum Leap, Firefly, and Babylon 5, and no mention whatsoever of DS9. But I have to agree with the number one. 1960s Twilight Zone episodes are still watchable. So, good and still absolutely excellent storytelling. I recommend any doubters of how good it still is, to watch a few. I record them and watch them on my DVR. Only a few stink.

Usually, I agree with your ranking, BUT Doctor Who only at #3?! I've been watching Doctor Who since Tom Baker was the Doctor. Should've been #2. Twilight Zone definitely #1.

Where's Deep Space Nine? It is the best Star Trek show by far.

Red Dwarf ftw!

X-files, Fringe, OG Dr Who..... Also The Expanse just for awesome realistic space. Babylon 5 had amazing CGI for the time. Raised by Wolves is an incredible show that, tragically, got cancelled. Foundation should have been mentioned too.

“Star Wars isn’t Science Fiction, it’s Fantasy, a Space Opera for 12 year olds”
-George Lucas

You missed out Blake's 7!

No deep space 9? WOW that was hands down the best Star Trek series ever. WOW the disrespect.

Outer Limits was the best sci fi show ever. And I will tell you why. It's because it was way ahead of its time than these other shows. And I have to say One Step Beyond was a better show than Twilight Zone even if it wasn't sci fi. And that's the bottom line cause Stone Cold said so (from 976-CREOLEMAN)!

Babylon 5 should be at least in the top 5.
Star Trek DS9 is THE best Star Trek show.

Stargate SG1 forever and always!
David Tennant Doctor for the win!

What??? No love for "The Lone Gunmen"?

Doctor Who WAS great, up until Russell T Davies left after his first run. After that? Well, current viewership and internet critiques tell you how bad it got.

My only sharp disagreement is "Lost". While I consider it to be a fine series, it was never science fiction. It's a fantasy that makes heavy use of metaphor and allegory to explore one version of the afterlife. Fiction? Definitely. Science? Only incidentally and occasionally.

No star wars?, space above and Beyond, Trek # 1, Dr Who #2, Fire Fly #3, Farscape #4

The expanse should be Much higher on this list.

Hecho en falta voyage on the botón pf the sea y space 1999

If you are still watching anything star wars, know we are too old. I do NOT watch any of that bs. Maybe, you could say twilight zone. Dark is a great nap or sleep inducer. The Expanse is #1 no doubt. reply if you want but I will not remove my vote. ALL TIME GREATEST

Doctor who 2005-2010. The goat.

how many adverts dam

Glad Quantum Leap and Orphan Black were there. I saw a few episodes of BSG and couldn't get into it. When I saw it cheap for complete series, I grabbed it, assuming it was just that I needed to see more and from the begin, as I love anything like that usually. Yet I tried watching through 3 times and every time they said "frack" or made a deity reference, which was far far too many times, it broke my focus and ended up selling it. If they had just said fk, I may have coped with the deity references, but both together made me despise it. Then there was Starbuck, who looks like some bloke has been down a back alley for a budget sex change. I honestly don't get why everyone my end was going on about her being so hot. Even bit parts in The Big Bang Theory. I cringe when she's on screen, creepy.

A couple of those aren't SF. Mandalorian for once is space fantasy. And unfinished so how can one claim if it's good or not? However if you include space fantasy then Babylon 5 not being on the list is hilarious. And even if it is space fantasy - it is much closer to SF than some titles on the list.

FARSCAPE,FARSCAPE,FARSCAPE and don't forget FARSCAPE!

The X-Files are my all-time favorite show #1, it's the best. Stargate SG-1 is my 2nd all-time favorite, and thanks for the mention here, since it seems very underrated, unknown by most. I love Battlestar Galactica, Firefly, Stranger Things, and, Star Trek: The Next Generation, too. I believe TNG is my current favorite #3, since everything beyond 2, tend to switch around.

Shows that checked all of the boxes for me: Dark, Fringe, The Expanse

Highly recommend

I couldn't take this seriously when it started off with a C or D rated show as part of the list. Just because the Mandalorian was the best Disney Star Wars doesn't mean it didn't suck -- it sucked.

Just finished watching THE MANDALORIAN that is why i came here to search for another.

Greetings from Brazil ...

I missed at least one of Irwin Allen's shows ... Lost in Space, Voyage To The Bottom of The Sea, The Time Tunnel or Land Of Giants

The Twilight Zone isn't really sci-fi though - it's more on the paranormal side. There are stories about death, ghosts, etc. But it still holds up today although I also love the Eighties version. There are some GREAT episodes in that series as well.