Dune is an incredibly influential series of sci-fi novels by Frank Herbert. Since then, it's been adapted to all sorts of media, including boardgames, video games, two mini-series and a movie. Surprisingly, we are not all that obsessed with it, but we do respect Dune for all it's done for sci-fi.
 Overall Setting
Dune is a desert planet, inhabited by desert ninjas, psychic nuns and giant tank-eating worms. To sum up the first of the books: it's much like Lawrence of Arabia IN SPAAAACE, people don't trust machines so they learn kung-fu of the future, and instead of computers there are dudes that are Rain Man on steroids. The plot revolves around a monopoly on a spice called 'melange' that extends life, heightens peoples' mental abilities to the point where they can foresee the future (required for faster-than-light travel), and it's as addictive as cocaine, heroin and World of Warcraft rolled into one. Naturally, people take this stuff seriously.
Dune is probably one of the most in-depth science fiction books ever written, considering the utter detail that goes into sociological, ecological, political theory, economic elements that are added so neatly. It's like a textbook, only far cooler. Opinion on the later books in the series is split, with some feeling it's a continuous decline in quality through to the end, an increase in crap until you're four books in when you notice you're reading a doorstop chiefly composed of Leto whining that turning into a sandworm is haaaard, while others feel the next three books are crucial to understanding the themes Herbert started to explore in the original Dune (especially the damaging effects of hero worship on society). Still, everyone agrees that the prequels and sequels written after his death by his son are irredeemably bad, so avoid those unless you're a devout Slaaneshi follower trying to experience the whole spectrum of human emotion and the next thing on your list is mind-numbing disappointment and boredom.
 The Movie
The David Lynch movie absolutely sucked (saying this out loud is a good way to troll hipsters). If you want a good laugh I'd suggest you watch it -- it's not often that you'll see a fetal manatee shit lasers. It's a classic case of Hollywood taking an amazing work of art and deciding "the audience" won't like it, so they get rid of the parts they don't understand. If you've read the book, the butchery is even more
hilarious cringe-worthy full of lulz, though I suggest you don't watch the movie first. Who, after all, would want to read the Odyssey after seeing the movie? (I'd suggest you see the movie as well, as it is also that bad awesome. )
There's the mini-series made by the Sci-Fi Channel. Three 2-hour parts, but they do manage to touch on each of the important plot points from the book, and there's no skimping on the action to make "weirding modules" toys to be sold as merchandise.
 As an RPG Setting
Frank Herbert went into SO MUCH DETAIL in his novels, you've got plenty of material to use as a campaign setting. You've got politics, fightan, enough politics to give Machiavelli a headache, and room for quasi-magic shit. Go nuts.
There was an official Dune RPG, "Chronicles of the Imperium," but it got mired in legal bullshit, and then Wizards bought it out, did a 'Limited Edition' run of 3000 books and then the high masters at Hasbro said "no more licensed property" and eighty-sixed the game so nobody would see it ever again. Assholes.
Someone made a homebrew GURPS Dune splatbook. I had it around here somewheres.
 The Games
The videogame Dune 2 is hailed as the first RTS game that got it right, and paved the way for all the others. It's widely-accredited as putting Westwood on the map. It was remade in 1998 as part of a renovation attempt, and the resulting game, Dune 2000, was a fun if somewhat off-centered RTS boasting fairly decent balance and was great fun to play in multiplayer LAN games, but it was hindered by the fact that the bulk of its gameplay had been lifted from Command and Conquer, creating a sort of hybrid that (justifiably in some cases) pissed off fans of both franchises. Then again, it had fucking Gimli as an Atreides Mentat, a kickass robo-Mentat that gets progressively more drugged out for the Ordos, and a good atmosphere and set design reminiscent of the good aspects of the Lynch film, so even then it has some good qualities.
There's three boardgames worth mentioning that were based on Dune. The first and best remembered is the Avalon Hill game made in 1979 by the same guys that made Cosmic Encounter, it's one of the crown jewels of the Avalon Hill body of work. The game property was bought by Final Flight Games, but the owners of the Dune trademarks said "no," so FFG published the game using their Twilight Imperium setting as a prequel to that wargame. need more talk about the fuckawesome 1979 game
There was an trashy tie-in merchandise boardgame based on the David Lynch movie. Paper pasted on cardboard, roll-and-move race game, typical Ameritrash. The less said about that, the better.
There is a free print-and-play game "Dune Express." You can use simple coloured dice, Skittles for your armies and draw the map on the back of a pizza box, and yet it will still feel like great houses fighting over Arrakis. A decent beer-and-preztels game without being hurr durr dumb.