Faulkner is my second favorite author after Shakespeare, but he does take some getting used to. I would recommend trying either The Hamlet or some of his short stories before you move on to The Sound and the Fury. In Faulkner novels, you should read slowly, and after each scene, stop and think about where it fits in the overall narrative.
As for Ulysses, it can’t hurt to start it, and you’ll soon find out whether you like Joyce’s style or not. Portrait of the Artist as a Young Man is much shorter and easier to follow.
I only got through about 600 pages of Atlas Shrugged, but I did read the entire Cliffs Notes, and that alone is pretty tedious. Too many characters going through the same process of self discovery, too many annoying subplots, too long, too tedious, too repetitive.
I would strongly recommend Tess of the d’Urbervilles and Jude the Obscure by Hardy as well.