Oh, I thought you were a newbie; you're an expert! I never really read much of the comics or YA novels either, except for Dark Empire, because I was tired of references to the revived Emperor that I didn't understand.
The X-Wing books are great, but take place in a few spots in-between the other books, so that'll be a fun revisit of older stories. The New Jedi Order is a re-envisioning that is over a massive number of books, but feels like every book goes so fast or has major consequences. Be prepared to be upset about characters you might love, but I think it's close to the peak. I believe the many authors got together and plotted out the whole thing before it started, which is nice. What comes after is okay, but I think they knew Disney was buying by that point, so there's not a great "ending," even if some novels are still delightful. Also, if you haven't read some of the Tales books, like Tales of the Bounty Hunters, those are fun (mostly) self-contained stories you can hit in-between the main novels.
Man, I wonder if I should start a full reread. I'm sure I've forgotten so much that I would still be surprised by plots.