A cult TV series is any show that has a dedicated and loyal audience. So, a better question may be, “Why does Twin Peaks STILL have a dedicated and loyal audience, 25 years later? In my opinion there are three main reasons:
The look of the show. Twin Peaks was the first real “cinematic” TV series, in that David Lynch directed a beautiful pilot that looked unlike anything else on TV. Later episodes continued to show amazing and bizarre images that, again, you didn’t see on Magnum P.I.
The feel of the show. Twin Peaks was a very DARK show, and dealt with very disturbing ideas almost from the first scene. These scenes were creepy and disturbing as Hell, and still frighten today (the episode where BOB was revealed has one of the most unsettling sequences that has ever been broadcast).
The characters and the writing. While the look of the show was almost all David Lynch and the show’s other directors, the characters and dialogue was quirky strange and wonderfully realized. Give full credit to co-creator Mark Frost for bringing that sensibility to the table. Peaks without him would be gorgeous, disturbing, but hollow inside.
Three legs of a stool that Peaks sits proudly upon. Now, if you will excuse me, I have to find out what these wonderful trees are…