Yes, I have fandoms I just stick to canon for - sometimes it's because no-one else can quite get the voice right (I have read some good Discworld fic, but mostly backbutton after the first sentence) and sometimes it's just because the original feels so perfect and complete in itself that attempting to add anything else just seems wrong. (I think Le Guin falls into this category - I adore her books, and somehow don't even want to look at any related fic.)