Yes the reborn emperor was in Dark Empire where Palpatine was cloned and brought back to life in the labs on Weyland. It was a good series that was followed by the Crimson Empire series which was set in the same storyline.
Probably the best though, is the Thrawn Trilogy. I think most fans agree that Grand Admiral Thrawn was one of the best spin off characters and Timothy Zahn, who wrote it, is one of the best star wars writers. The artwork in the comics is superb, nothing is better than seeing the Katana fleet with the new super star destroyers.