The Expanded Universe was always enjoyable to read, maybe not the greatest works of literature ever, but you got to see how life was progressing post-Return of the Jedi, you got to see how Luke, Leia, and Han's family and friends lived and died.

There were some pretty good authors involved over the years too, like R. A. Salvatore, Timothy Zahn, Kevin J. Anderson, Michael Stackpole, Karen Travis, William C. Dietz, Kathy Tyers, among many others. If you read any other seriailized series like the D&D novels, Battletech/Mechwarrior, Star Trek, Warhammer, and all of the many others that exist, you will probably recognize some of the authors as writers in those series as well.

As for the Prequel books and other novels post cancelation of the Star Wars Expanded Universe there was some quality improvement per novel as the universe became more definitive and more in line with the cinematic universe.

As a lifelong Star Wars fan who read the EU books for around twenty years, I'll say I miss the version of Star Wars they were building, it wasn't always the heroes winning the day, there was plenty of heartbreak and betrayals to go around, but it was familiar and enjoyable.