How did I forget Dune?? I thought about how to answer your question for a day, then forgot half the answer.

Dune is absolutely great! The science is spot on, the writing sucks you in, the characters are so appealing, each with their motivation and ideologies. Everything is just amazing. It builds a whole galaxy by looking at only a handful if characters, all on the same small planet. It’s still revolutionary, in particular its focus on ecological terrorism is extremely modern.