Published first in 1965(!) Frank Herbert's masterpiece is still one of the best Science Fiction novels ever written. And unlike other works of its era it has aged really well, Dune is still as timeless and relevant today as when it was first published more than 50 years ago.

The term "universe" has been strained pretty hard by using it for loose collections of superhero movies based on DC or Marvel characters, but Herbert really creates a whole universe in one book, or at least a considerable part of a galaxy, making Dune a must read for every Science Fiction fan.

It's also the first part of a series, but later additions by Frank Herbert are not as compelling to me as the original work (especially after part 4, "God Emperor of Dune") and the even later prequels and sequels written by Brian Herbert and Kevin J. Anderson, while not bad as "popular fiction" in their own right, just don't play in the same league.