Dune by Frank Herbert
Id recommend Iain M Banks. He writes thrillers and horror as Iain Banks and Science Fiction as Iain M Banks. In particular he uses sci fi to look at the structure and politics of society, in particular at the concept of utopianis
Read it, albeit along time ago. Brilliant.
Spares sounds good, I'm getting itMichael Marshall Smith writes some great Sci-Fi, only forward and spares are great if you have not read them already
Don't be put off by the fact that some of these were first published 50+ years ago.
Completely forgot Philip K Dick, Do Androids Dream Of Electric Sheep is a good place to start.
Kim Stanley Robinson's Mars trilogy is a modern classic.