Went downhill during "Children"...
Dune 1-Good, but overly complex. I put it down and picked it up again several times before I finished it. On a scale of 1 to 5, 4.
Dune Messiah: Top twenty of all the books I have ever read. More focused and coherent than the first novel. 5 out of 5.
Children of Dune: The ending ruins the interesting setup made at the start of the novel. Reminded me of the feeling I had after watching The Phantom Menace: so much potential, ruined... 1 out of 5
God Emperor: Slightly better than Children of Dune, but Leto II's endless philosophical ranting got on my nerves after a while, especially since you have to listen to his drivel in the excerpts before the chapter AND within the chapters themselves. It was like listening to a four thousand year old senile grandpa. He is not nearly as good a character as his father, Paul "Muad'Dib" Atreides was, and fails to fill the void left by his absence. 2 out of 5.
Thinking of reading "Heretics" and "Chapterhouse", but if they are catastrophes like "children" or absolute bores like "god emperor", i might not bother. "Dune" and "Messiah" are definitely keepers, though.