I simply don't like the universe Dune presents. A universe with the choice between being ruled by either a brutal autocrat, a benevolent autocrat or a jihadist sect following some "messiah" is not really a universe I like to be read quotes from.
If you need a sci-fi-quote from me its the end of "Roadside Picnic": "HAPPINESS, FREE, FOR EVERYONE, AND LET NO ONE BE FORGOTTEN!"
Else I'd go for the end of "Shockwave Rider" too.