According to TV Guide
1. Star Trek
2. The X Files
3. Buffy the Vampire Slayer
4. Farscape
5. Monty Python's Flying Circus
6. The Simpsons
7. The Prisoner
8. The Twilight Zone
9. Xena: Warrior Princess
10. PeeWee's Playhouse
11. Mystery Science Theater 3000
12. Family Guy
13. Babylon 5
14. Beauty and the Beast
15. Quantum Leap
16. My So Called Life
17. The Avengers
18. Dr. Who
19. Dark Shadows
20. Twin Peaks
21. Mary Hartman, Mary Hartman
22. H.R. Pufnstuf
23. Forever Knight
24. Absolutely Fabulous
25. Freaks and Geeks
I think it's rather a silly list, much, much too weighted towards recent shows, and ignoring older shows that had huge cult followings, such as Get Smart, I Spy, The Man From Uncle, Green Acres, etc.
And it omits what might actually be the biggest cult show of all, Saturday Night Live.
Here is my list of the top shows.
Adam 12
Batman
Green Hornet
Voyage to the Bottom of the Sea
Andy Griffith
Thunderbirds- I loved this show.
Fireball XL-5
Space 1999
Gilligan's Island
Happy Days
Gigantor
The Banana Splits Show
The Life and Times of Grizzly Adams
Land Of the Giants
Star Trek
Please Don't Eat the Daisies
The Mod Squad
Here comes The Brides
Hogan's Heros
Well thats enough, of that.
I underlined the shows from each list I have watched at least a few episodes from.
I can't believe they left off shows like Rocky and Bullwinkle,
Ren and Stimpy, Johnny Quest.