I was a member of the Arakeen forums a few years back. I've recently re-read Dune, Messiah and Children about 5 times each and was looking around the internet for a new board to come look at with other Dune dorks, like myself.
I don't remember the first time I read Dune...I'm 100% sure I saw the David Lynch movie first, and was facinated by the landscape. I read Dune for the first time probably within a year or so after the movie came out, and then I didn't re-read it until about 1992-1993 when I was in my first year at undergrad in East Lansing, Michigan. And then I read the series through Chapterhouse a few times....I bought a copy of the Dune Encyclopedia (yea, the rare one that isn't very accurate)...started playing an online text based Dune roleplaying game...and pretty much became convinced that if I smoked enough pot I might be able to see through the veils of time - which still hasn't worked.
I must have purchased Dune (book 1) at least a dozen and a half times from the same used book store and have given then out to friends and co-workers like mormon's hand out bibles - i'm quite sure the book store owner believes i'm a serial killer or something.
I bought a new paperback of God Emperor a couple days ago and started reading it again...for some reason, i've always thought of God Emperor as its own book. I've always thought of Dune, Messiah and Children as "book 1", God Emperor as "book 2", and Heretics and Chapterhouse as an incomplete "book 3". I think it's a chronology thing more than anything.
Finally, I've read a lot of the other Dune based books...the Butlarian Jihad books...the other prequel time books that KA wrote - House Corrino/Atreides/Harkonnen...I've read Volumes 1 and 2 of "book 7"...I even got through the first 2 chapters of Paul of Dune. But, the writing is pretty horrible...the plot lines don't coincide with Frank's original material...and I really don't think I'm going to even finish Paul of Dune (which has been sitting in my bathroom now for almost a year), nor will I even re-read any of the other Duneish prequels.
That's my Dune history in a nutshell, I'm happy to let me water flow through your spirit river.