Over the years I've loved (in no particular order):
Star Trek (primarily TOS, TNG and DS9, but really just Star Trek in general)
Star Wars (Droids, Ewoks, Clone Wars, other Clone Wars, Rebels, Resistance, Mandalorian)
Stargate (SG1, Atlantis, Universe...still trying to find the rest of Infinity online, didn't hate Origins like many seem to have)
Doctor Who (including - to varying degrees - Sarah Jane Adventures, Torchwood, Class, K-9, K-9 & Company, Doctor Who Confidential, etc.)
BBC Hitchhiker's Guide to the Galaxy
recent Dirk Gently series
Twilight Zone (mostly original, first season of the latest one was...fine, haven't seen the 2nd season yet or the reboots in between the first and latest series)
Outer Limits (new & old)
Dark Skies
Space: Above and Beyond
Knight Rider
Voyagers
Quantum Leap
Red Dwarf
The Orville
The Expanse
Killjoys
Dark Matter
Firefly
Farscape
Fringe
Freakylinks
X-Files (including Lone Gunmen and Strange Luck, haven't finished Harsh Realm and Millennium yet)
Earie, Indiana
Tron cartoon
Space Force
Battlestar Galactica (new & old, though I've only seen the first season and a half or so of the new)
Babylon 5 (including Crusade)
Brain Dead
Black Mirror
Utopia
The Aliens
Sapphire and Steel
Rick & Morty
Futurama
3rd Rock from the Sun
Eureka/Warehouse 13 (haven't seen Alphas yet)
SeaQuest DSV
Earth: Final Conflict (season one only) (thanks
od0_ital)
Sliders (season one only)
Andromeda (minus the last season or so)
Red vs. Blue
Thunderbirds
Dark Crystal
Gen:Lock
Stranger Things
Buck Rogers in the 25th Century
The Pretender
Forever
Orphan Black
Defiance
Walking Dead shows
Solar Opposites
Plus others I'm sure I'm forgetting (don't be surprised if I edit this to add more).
Plus enough Saturday morning cartoons for their own post.
Plus enough super hero/comic book shows for their own post (if not thread).