I, Jedi isn't a bad pick from the extended Star Wars universe, but the best one is probably Timothy Zahn's Heir to the Empire series.
Also, I know everyone has read Ender's Game, but has everyone forgotten Speaker for the Dead? Ender's Game is a good novel, but even the author only thought of it as a semi-necessary prequel to Speaker, which had a lot more creative energy and imagination poured into it.
And no one likes Vonnegut? Slaughterhouse 5 was probably his most famous novel, but Cat's Cradle was by far my favorite.
Someone already mentioned Dune which is possibly my favorite traditional novel if I had to pick one. The 4th in the series, God Emperor of Dune, is great too.
Since we didn't disqualify comics, I want to also say that Alan Moore's Top 10: Season 1 is probably the best cop drama ever written.