Of course, “fantasy” is probably redundant, given that we’re talking about sentiient spiders. I want to contrast menacing and beneficient figures. I’ve already thought of Shelob, Ungoliant, and Charlotte; can anybody else name any? (Along with the titles of the books and names of the authors, of course.)
Piers Anthony Xanth novel “Crewel Lye” contained a sentient spider accidentally bespelled into a tapestry with our hero. There’s a humporous scene where the spider interprets a hostile act as being a sign of friendship and an overture of friendship as an act of hostility.
Vernor Vinge’s sci-fi novel, A Deepness in the Sky, is about a race of sentient, spider-like creatures that hybernate for about half of their solar year, and a ship full of humans who land on their planet during their sleep cycle. The novel cuts back and forth between the humans, who are in the midst of a deadly political crisis, with betrayals and murders and acts of hideous inhumanity, and a family of spider-creatures (from just before the humans show up) having, essentially, a big Nancy Drew/Hardy Boys adventure. It’s sort of funny, reading the adventures of these plucky teenagers uncovering a groovy mystery, and then remembering that the teens in question have eight limbs, compound eyes, and a tendency to drip ichor.
In Stephen King’s book It, It took the form of a giant spider near the end (or so I’m told, since I’ve erased that part from my memory and I’m more than content to be super-freaked out by the clown).
For a benevolent balance, there’s Miss Spider from Roald Dahl’s James and the Giant Peach.
Geez, many years ago I read a couple few books which were part of a series about a future dominated by sentient spiders. I can’t remember the name, but a quick google search turns up the Spider World series by Colin Wilson.
I can’t guarantee those are the books I read. I popped off an email to my friend who I think may have originally loaned me the books to see if she remembers.