I played Dune 2 first (in ~1993), then saw Lynch's Dune, then played Dune 2000, and then saw the Dune miniseries and Children of Dune (which, in a fan move, I posted on Usenet and got me my first and only DMCA warning from the MPAA :^). 10 years or so later, I bought the book Dune, and a few years later I finally read it. It is a legendary book indeed, but I wish I read the book first.

If you can, please read the book first before seeing/doing anything else in the universe. Don't let your imagination be spoiled!

(I'm not very interested in reading the sequels. Children of Dune was a terrible movie, IMO.)

Which makes me wonder what I missed with regards to J.R. Tolkien and George R. Martin.