Never been a huge fan of the Dune series. The first book I thought was very good, but I disliked it. Then the books got steadily worse, rapidly turning into what IMHO was bloated crap.  Again, Dune I is an excellent SF book. It's just that its worship of a mix of radical green mysticism and fascism rubs me the wrong way, and it's not quite good enough for me to forget about the political/religious aspects.

Late sixties through the early eighties was a sort of golden age of ambitious SF. There was some earlier, and it continues to this day, but by now much of it is getting published in the small presses. This past month  or so I re-read an excellent example of the seventies product, Joanna Russ' Female Man, some very idiosyncratic classic fifties and early sixties SF, namely a collection of Cordwainer Smith's Instrumentality stories, as well as Jeff Vandermeer's City of Saints and Madmen and I'm currently reading his new novel Shriek: An Afterword.  All recommended.