@NoX: I've probably enjoyed Frank Herbert's original Dune tome the most.
The movies are pretty fun, in a campy sort of way, and so are the FMV sequences in the RTS games.
And, maybe there's just a tiny little bit of rose-tinted glasses to this, but I find it baffling how much personality they managed to bestow upon the Mentats in Dune II
(particularly Radnor, House Harkonnen's amusingly evil Mentat - describing a Harvester, for instance, "Altough unarmed, the iron clad harvesters can be used effectively against small groups of infantry by crushing them beneath their treads.
Even the honesty of the Atreides is conveyed in a suitably enjoyable manner as well - Cyril, the Atreides Mentat delivers the following introduction: "Greetings, I am your Mentat Cyril. Together we will purge this planet of the foulness of the other Houses
"; now that's candour right there.
While it would seem most evident that such a universe would be best suited for an RPG or an adventure game adaptation (for the sake of exposition), the RTS titles worked remarkably well as an intro to the setting and have no doubt done wonders for the sales of the novels themselves over the years.
Some recent noteworthy developments involving the IP do give reason to take some heart in future undertakings - for instance, the new movie has already given us a great tabletop strategy game called Dune: Imperium