Because I have no interest in anything outside of the 1977 Star Wars universe, these four books will probably be the extent of my involvement with the EU;
Splinter Of The Mind's Eye
Han Solo At Star's End
Han Solo's Revenge
Han Solo And The Lost Legacy
I've read Splinter Of The Mind's Eye and really enjoyed it. I haven't read the other three yet. I did read the first chapter of Han Solo At Star's End and really dug the feel, so I look forward to jumping in.
The Han Solo books were recommended to me by members of this board because they fit the universe I'm interested in, and because they were written by Brian Daley. He wrote the NPR version of Star Wars - my preferred way to experience Star Wars.
I have two books ahead of them so I won't get to them until this summer. I'll probably read Splinter Of The Mind's Eye again after that. If I find any others that fit within the 1977 Star Wars universe, I'll look into them.