Earlier quoted context omitted.
Read the 6 books by Frank Herbert, skip the other spin offs by his son and the other guy - they're terrible in comparison.
I never though much of Dune 2-5 either, but I guess I'm in the minority on this one.
I think the reason people have trouble with 2-6 is that they're ultimately a reversal or deconstruction of the Hero myth. The first book is a fairly typical "Rise of the Superhuman Hero" tale, and that's why it's accessible. Book 2-6 explore the dark side of this myth, which is why they're unique, somewhat inaccessible, and really interesting.