I can confidently say that Frank Herbert’s original six novels are the cornerstone of the series. Start with 'Dune', a masterpiece that blends politics, religion, and ecology into a gripping narrative. The sequel, 'Dune Messiah', delves deeper into Paul Atreides’ struggles, while 'Children of Dune' expands the saga with its rich character development.
For those who crave more, 'God Emperor of Dune' is a philosophical gem, though its slower pace isn’t for everyone. 'Heretics of Dune' and 'Chapterhouse: Dune' introduce new factions and conflicts, rounding out Herbert’s vision. If you’re hooked, Brian Herbert and Kevin J. Anderson’s prequels and sequels offer additional lore, but they lack the depth of the originals. Stick to Frank’s works for the purest experience.