My 2c....
I start with the word "classic." It seems to me to imply longevity. A classic has been around long enough to have proven its capacity to appeal to and to reward readers of different generations.
Then there's the matter of "how long"? It seems to me we have to factor in the length of time that a type or genre of literary art has been around. If we want to refer to classic drama, for example, we would be aware that surviving drama of unquestioned literary merit goes back over 2,000 years. This being so it would be (in my view) rather casual to refer to something composed in the past few decades simply as a classic dramatic work. One could add something that reduced the amount of time implied. Thus it would seem fine to me if someone wanted to argue that Miller's Crucible is a classic of American drama. That sets up a much shorter time span. I'd prefer not to refer to The Crucible simply as a classic work of drama in such a way that we were implying it ranks with sophocles and Shakespeare.
So, then, I would suggest that the question posed by this thread is really about classics of modern fantasy (in English). Influenced by Lin Carter, many people would suggest that the genre of modern fantasy begins in the late Victorian period with the romances of William Morris. Let's say we're dealing with a period of about 125 years, then. I would think that we are using the word "classic" rather loosely if we start awarding it to work published in the past few decades. Isn't it a bit premature to say that XXXXXXX by XXXXXXX, published in 198- or 199-, is a "classic"? Personally, I would be willing to characterize Le Guin's Earthsea that ends with The Farthest Shore (1972) as a classic work.
And of course a classic must have literary merit. Surely there's no question about that as regards these Earthsea books.
Again--that's my 2c. If others disagree, okay, but could they explain how "classic" may be differentiated from just "my favorite."
Now as regards "classic fantasy era"--
Three periods stand out to me.
1.The 25 years 1887-1912, in which so many classic works (Haggard, Morris, MacDonald, Dunsany, Hodgson, et al.) appeared; this was when science fiction and fantasy weren't really differentiated, and so it includes the best of H. G. Wells, Doyle's Lost World, etc.; it also includes classics of what became known as "dark fantasy," such as Dracula, Blackwood's "Wendigo" and "The Willows," etc.; this was the Golden Age
2.The approximately 20 years between the appearance of The Hobbit and the final Narnian book (1937-1956, I think), which would include LotR, the T. H. White Arthurian books (I'm not sure I will find those to have held up well if I return to them), Unknown magazine, The Dying Earth, etc. Tolkien dominates this period.
3.The approximately 10 years in the late 1960s-early 1970s that includes the Earthsea books, The Last Unicorn, Watership Down, etc. This would also include as a notable event the Ballantine Adult Fantasy series of reprints and new works (1969-1974 or so), if that's relevant. The establishment of fantasy as a distinct paperback publishers' niche dates to this time, it seems to me. In the late 1960s A Wizard of Earthsea or Avram Davidson's The Phoenix and the Mirror could be paperbacked by Ace as a "Science Fiction Special"; but by the end of the period that would be highly unlikely, surely. It was fantasy and publishers knew by then that lots of people would read readily sf but not fantasy, and vice versa.
I offer all of the above for discussion....
There are a number book s published after that might fit the category of Classic post 1980 to consider. The Anubis Gate by Tim Powers written 1983 . This should be considered a classic and so Mythago Woods by Robert Holdstock . written 1984. There other post 80'd books that fit the definition of classic.
