Willow offered a list of fantasy books, most of which were new works and many part of a series. Here's a counter-list of books that, with some exceptions, are older stand-alone novels or short story collections that I'd suggest as Fantasy Books to Read in a Lifetime. But why be picky? Read all of both lists!
Three caveats: First, there are some titles on both lists; second, since my taste leans toward darker work, some of these titles veer toward horror, but I think all could be argued as fantasy, too; third, there are a few that present as science fiction, but which include elements of fantasy (or of a science so advanced it looks like magic).