Recommendations from previous threads...
Rise of the Empire Era
- Rogue Planet (if you plan to read The New Jedi Order; I don't recall liking this book all that much back when it was released)
- Republic Commando series (you better like Mandalorians, though - also, Imperial Commando 501st is the last novel featuring these characters)
- Shatterpoint
- Labyrinth of Evil
- Dark Lord: The Rise of Darth Vader
- The Han Solo Trilogy
- The Adventures of Lando Calrissian
- The Han Solo Adventures (Brian Daley's works, which I recall as being fun as hell, though I haven't read them since my early teens - there's also, if I recall correctly, a point in A.C. Crispin's Han Solo Trilogy where its story takes a sort of "break" where one could then easily read these books)
Rebellion Era
- Splinter of the Mind's Eye (the first non-novelization SW novel; originally intended as the basis for a low-budget Star Wars)
- Shadows of the Empire (takes place between The Empire Strikes Back & Return of the Jedi)
New Republic Era
- X-Wing series (keeping in mind that the last two books - Isard's Revenge and Starfighters of Adumar - take place following books outside this series)
- The Courtship of Princess Leia (I don't recall much about the quality of this one, but it is pretty important as far as the future of the EU goes from this point on)
- The Thrawn Trilogy (pretty much a must - the first post-ROTJ novels published, though some time has passed since ROTJ)
- The Jedi Academy Trilogy (not great stuff, but pretty important for the establishment of Luke's new Jedi Order)
- I, Jedi (just fantastic, and a great companion piece to both the X-Wing series and the Jedi Academy Trilogy)
- Darksaber (again, no recollection on quality, but some important characterizations here for later works - at one point, I had a copy signed by Kevin J. Anderson but no clue where it's at these days)
- The Corellian Trilogy (I do recall mostly enjoying these books, and some events here are important in later books as well)
- The Hand of Thrawn Duology (more Zahn work, based on his earlier Thrawn Trilogy - good stuff, as I recall, plus important in later books)
- Young Jedi Knights series (surprisingly good for YA books, though I've only read the first six; also, they introduce and flesh out many characters who are important in the NJO and beyond)
New Jedi Order Era
- The New Jedi Order series (some of it is average, some is good / very good, some is great; my favorite SW novel period - Traitor - is in this series)
- The Dark Nest Trilogy (I enjoyed it well enough, plus some events are very important in LOTF)
Legacy Era
- Legacy of the Force (I enjoyed most of it, but I do agree with some criticisms that I've seen that parts of it feel as if the series was too long, too drawn out)
- Crosscurrent (pretty fun; worth noting that it focuses on a Jedi introduced in the Jedi Knight: Jedi Academy video game, and features none of the original and/or other popular EU characters)
- Millennium Falcon (pretty fun, plus worth it to spend some time "alone" with Han & Leia following the tragic events in LOTF)
- Fate of the Jedi (read the first seven so far, and enjoying it; worth noting that one might want to consider reading the "Lost Tribe of the Sith" eBooks either prior to or in conjunction with this, as they spell out some of the history of the Sith in this series)
If I haven't mentioned a post-ROTJ book above, then odds are it wasn't worth reading (if published back in the Bantam days) or it was published after I wasn't reading SW novels quite as voraciously as I once did (i.e., some of Zahn's newer stuff, Luke Skywalker and the Shadows of Mindor, etc.). As for books set in the Clone Wars, I haven't read most of those, nor have I read any of the books in the Old Republic Era yet.
For some examples of those that I consider not worth reading: Children of the Jedi; Planet of Twilight; The Crystal Star; The Black Fleet Crisis Trilogy; and The New Rebellion. Unfortunately, there is a rather important mention during the FOTJ series of one character who is in a few of those books, but one would probably be okay to still skip those. Of course, she also appears in Darksaber, so it could be odd to have her show up in that one without the context of her first appearance and the ones after Darksaber.
For comic recommendations (out of the many comics series that have been published, I have unfortunately read very few, so I'm not going to bother separating these into eras):
- Tales of the Jedi (nicely collected in two Dark Horse Omnibus editions)
- X-Wing Rogue Squadron (chronologically take place prior to the X-Wing novels, and introduce some characters important in those novels - collected in three DH Omnibus editions)
- Dark Empire Trilogy (Dark Empire, Dark Empire II, Empire's End)
- Legacy (great stuff, 140 years or so after A New Hope)