Showtime
(launched in 1976)
IMDb; official website; TV Tropes; Wikipedia

I've never had access to this network, but I've seen a bit of its programming elsewhere, and there are some things I'd like to see someday.

Faerie Tale Theatre (9/11/1982 - 11/14/1987; I believe I saw this on PBS)
The Outer Limits (3/26/1995 - 9/3/2000; s7 aired on Sci Fi; I must have seen some of this in syndication)
Sabrina the Teenage Witch (4/7/1996; TV movie)
Snow White: A tale of Terror (8/24/1997; TV movie; I saw this on DVD)
Dead Like Me (6/27/2003 - 10/31/2004; I saw this on Sci Fi)
Reefer Madness (4/16/2005; TV movie; I saw this on DVD)

stuff I want to see
Bastard Out of Carolina (TV movie)
Californication
The Devil's Arithmetic (TV movie)
Gotham (TV movie; aka "The Dead Can't Lie")
Homeland
Jeremiah
Masters of Horror
Nightmare Classics
Penny Dreadful
Robin of Locksley (TV movie)
Tall Tales & Legends
The Tudors
Weeds
Yellowjackets
and maybe some other things