Well, the only reason they put so much science fiction into the EU is because you can only read about Jedi so much before it gets old.
The X-Wing series is great reading and almost pure SciFi with just a touch of Jedi speckled throughout. Same with the Han Solo trilogy, most of the Bounty Hunter stories, and part of the Lando trilogy. Heir to the Empire trilogy had a decent mixture of both.
Hilariously, the books that deal more with the force than anything else are easily some of the worst. White Current? Planets that amplify the force? Creatures from other dimensions that survive by eating force sensitives.... ugh.
Although anyone that says the Dark Empire comics are bad is my mortal enemy. If anything they get a pass just based on the coloring alone. Not to mention it's an amazing story overall.
The last series of the EU was some of the dumbest stuff ever. That weird immortal dark side cthulu monster was the dumbest of all the force stupidity in all the EU. And thats saying something. I loved the sci-fi stuff in the Yuuzahn Vong books though.