For any speculative fiction (by the most inclusive definition - if you think it might count, it counts) that exhibits "literary" traits such as: strong themes, thought-provoking ideas, deep emotional meaning, artful use of language, or so on. If a book "feels" literary to you, go ahead and add it.
This is highly subjective, of course, but I think it could make for an interesting open list. Let's see what we end up with :)