Dune

Put it on your short list.

Positives: Dune may not be the most intricately developed worlds (as in a whole galaxy) of inter-dependent, maladapted cultures of the possible futures every crafted in the English language, but it is in the top five for sure.

Negatives: It is a very complex world, and that might overshadow the lesser attention placed on the minor characters or sub-plots. -- That being said, there are only so many pages a publisher will print in one binding.

Conclusion: It won awards for a reason. It is on the "must read" lists for the same reason. Religion, economics, politics, space travel, intrigue, pathological narcissm -- at their worst, collide into a quintessential moment.