A basic knowledge of Norse, Greek, Celtic and Roman mythology is helpful for basic fantasy literacy. Evangeline Walton has written a nice set of books using Celtic mythology which would work as an intro for most people.
The Brothers Grimm.
The King of Elfland's Daughter by Lord Dunsany, he was one of the early fantasists.
Bridge of Birds by Barry Hughart.
Andre Norton's Witch World books.
Susan Cooper's The Dark is Rising quartet.
Lloyd Alexander's Taren series.
Lovecraft, duh, almost forgot him.
Almost forgot L'Morte D'Arthur or at least some familiarity with Arthurian legend
It'll be interesting to see what other people think too. I'm sure there are some I'm forgetting, this is just a top of my head list.
BTW, if you aren't talking about cultural literacy, but classics, I'd remove Wheel of Time, the Belgariad, Sword of Truth and Sword of Shannara from your list. They are popular, and I like the Belgariad for a nice bit of fluffy reading; but none are classics as either literature or by their influence on the genre.
edited 29th Aug '12 5:05:26 PM by Lightningnettle