12. Mara Jade
At different point in time she has been the Emperor's Hand, a smuggler, and a leading Jedi Master as well as a skilled pilot and mechanic. Her diverse skill set enabled her to become one of the most dangerous combatants in the Galaxy as well as an essential part of the New Jedi Order and a pivotal player in many of the most important galactic events of the time. She was instrumental in the Thrawn campaigns as well as the Caamas Document Crisis and was one of the leading Jedi Masters in the Yuuzhan Vong War. She has one of the more interesting character arcs of any expanded universe characters, going from die hard Imperial to committed Jedi. Her ship the Jade shadow has been overhauled by both Lando Calrissian and Han Solo to the point it's one of the most advanced ships of its size in the galaxy and she regularly tops fan polls of the greatest Expanded Universe characters.