I'd be willing to entertain Delany as outranking Le Guin, except that I *still* haven't read any of his stuff. (Dhalgren is just so... intimidating.)

Wolfe... I've never read any Wolfe either, but I've also never seen his work talked about in any context other than "Best SF writer" - ie nobody talking about how he had an influence or did new and different things or stirred up everybody in the genre or brought them into reading SF, or any of the other things people say about Delany and Le Guin (and Zelazny and Heinlein and a bunch of other non-living ones...) In fact I have no idea what Wolfe wrote about, whereas I have a pretty good idea about Delany just from following fan discussions.