Dune Chronicles, the 8 books, as I consider them one single long story told in +4000 pages. The God Emperor of Dune (4th book) I consider to be the apex of the story.
I'm kind of shocked that anyone would recommend anything after book 4. (Book 4 is the last one I would recommend. As far as I'm concerned you can get everything you need from summaries for everything after that.)
