This thread points out the problem with Top 100 lists, of SF or other large bodies of things judged subjectively, which is that there are far too many good ones to stop at 100. In the real world of course one would hope to have the time to read far more than 100 SF novels; fortunately for me I've read several thousand over the past 40 years. Personally, though, I wouldn't put Dune or any Gene Wolfe on my Top 100 SF n…
Try Wolfe's The Fifth Head of Cerberus and see if you might change your mind. It's very readable, and it's pleasantly short. It's half Borges, half Sturgeon, with a pinch of Ray Bradbury.