I've never managed to get through Ulysses, Gravity's Rainbow, or The Illuminatus, to mention some 'modernist classics'.

But I've read everything of Stephenson from Snow Crash through the Baroque Cycle. What makes him very readable for me is his inventive imagination and the way he expresses this without becoming embroiled in paranoia. NS insists that he's still working in the SF genre, even with the Baroque Cycle. I'd go with Speculative Fiction.

"The science fiction approach doesn't mean it's always about the future; it's an awareness that this is different". - Neal Stephenson