The best of the Star wars EU books was Timothy Zahn's Thrawn Trilogy. It takes place a few years after ROTJ and has some new villians, the Grand Admiral Thrawn, who has taken over the Imperial fleet, and Joruus C'baoth, an insane jedi who I think was light-side with dark elements. Written before the prequels, so elements of it now contradict the prequels, specifically what the clone wars were about, but I actually think the book had a better idea that ROTS. but it doesn't talk too much about them, so they are easly overlooked if you are really into everything fitting together and not contridicting. Other than that, Shadows of the Empire is OK, but I really hated the villian and thought that the ideas of the book wasn't very good. Not much else in the EU I really liked, though. I sort of stopped reading them after I couldn't get into the Jedi Academy Trilogy.