Have you read Dune Messiah and Children of Dune? I actually think that Children of Dune is as good if not better than Dune.

I read The Lord of the Rings as a child, and it felt like reading a translated mythological history of an ancient civilization. However, reading Dune felt like stepping into an actual temple built by the founders of an ancient civilization. Frank Herbert had such reverence and devotion to his own world that I don't think that anyone will ever top his accomplishment.

So yes. I do think that you should re-read Dune sooner or later.