I loved the original Dune, and the Dune2 game I was playing at the same time
Wasn’t really impressed with Messiah, Children and God, a little bit too descriptive and not enough things happening, but loved Heretics and Chapterhouse, for the opposite.
About the prequels, read through the “Prelude …” trilogy, which went from bad to worse. Not enough imagination, constantly jumping from one sub-plot to another, unnecessary characters and plots etc. If you liked the originals, these ones are better to be avoided. Haven’t tried the pre-prequels (“Butlerian Jihad” etc.) but after the Prelude disaster I’m not sure I want to.