Star Trek has only 540 hours of canon. You could watch it all in a month assuming you sleep 6 hours a day and spend the other 18 watching constantly.
–FCOD
What’s really weird is your post almost made sense!
The freaks into The Rocky Horror Picture Show.
According to the fans, there’s a formal, Lucas defined hierarchy of Star Wars canon; IIRC it’s basically Movies & Lucas produced data at the top as “A level canon”, the “Expanded Universe” of the novels and stories as “B level canon”, and videos games and some other stuff below that. It’s all canon unless contradicted by higher level canon.
That’s an awful lot of canon.
Plus it ran as a magazine from about 1933 to 1947. There’s the movie (I saw it!) and the Phil Farmer bio, and his two or three books starring Doc Caliban.
I’ve got nearly 100 of the paperbacks, and exactly one of the magazines.
There are 4 Clarke-authored 2001 books, btw. 2001, 2010, 2061, and 3001. But I doubt there is much of a cult around the latter 2 books, at least.
It’s not sci-fi, but I’d like to mention the series of Taster’s Choice commercials (Gold Blend in the U.K.) featuring Anthony Head and Sharon Maughan. Thirteen “episodes” (twelve in the U.K.) for a total “canon” of about 7 minutes. In its day, it had quite the following.
Max Headroom has to have a pretty short canon as well.
OMFG, that was Anthony Head?! So I had a crush on him from those, only to have a crush on him AGAIN as Giles. Huh. /hijack
Hardly any? So there are barely some? I’m interested! What are they?
-FrL-
You’ve never heard of Leave it to Reaver?
Wow. Kudos on this one.
They’re called “fanfic.” Don’t look. 
There’s a roleplaying game.
I meant, spinoffs into other media, like the comic books. And apparently the roleplaying game Quartz mentions.
The fandom of Gargoyles, the mid-90s Disney cartoon, deserves mention for their sheer persistence, if nothing else.
The first two seasons consisted of a total of 65 half-hour episodes. The third season was another 13 episodes, only one of which was considered canon by the fans and the show’s creator. That gives an accepted video canon of roughly 33 hours, or 1980 minutes. There was a brief (11-issue) Marvel comic run of Gargoyles, which didn’t follow the series continuity. It is not generally considered canon, although it doesn’t face the antipathy that Season 3 did.
That’s it. You could get through all the canon in a weekend, and still get a fair amount of sleep. If you go a little short on sleep, you could cover all the non-canon stuff, too. From this arose a following that has held annual conventions since 1996. There were letter-writing campaigns urging a rebirth of the show. There was fanfic and fanart, some of which was collected and published in an anthology.
This year, a new comic book series hit the shelves, written by the series creator and picking up where the cartoon canon left off. The fans are getting at least some of what they’ve been hoping for.
I liked Pitch Black a lot, with a sci-fi story using 3 suns and an anti-hero.
Sadly they then released Chronicles of Riddick, which was just a shoot’em up.
Four novels and five short-story collections by Conan Doyle. You missed The Valley of Fear for the novels. The collections were The Adventures of Sherlock Holmes, The Memoirs of Sherlock Holmes, The Return of Shelock Holmes, His Last Bow and The Case-book of Sherlock Holmes.
flaps in
You rang?
flaps out
I did and I find it stangely enjoyable. I know dudes are thinking you are joking but the later books are barely canon, and are drek.
I think we’d have to say a SF cult would include regular costumes at SF cons. OK? And when they have their own fucking convesntions, it clearly is a cult.
Firefly definately qualifies under that.
Doc? Not so much.
Okay, that made me laugh out loud.
Can you imagine it? That would be the awesomest sitcom EVER.