This is a really hard question for me to have a definant answer to (between Ra's, joker, and bane). Ra's al ghul had the most combat knowledge and was the most wise, basically gave rise to batman and bane, and in my mind the biggest threat in a fight, yes even more than bane. The key thing with Ra's was, if you really think about it, he was right. You would all agree that people like Hitler, Stalin, or Jeffery Dohmer need to be killed right? Well gothem is the eqivilent to thoose just on a larger scale. The joker was by far the most evil and influencial on each charecter. The joker was very smart and incredibly manipulative which may have been the scariest thing about him...turning harvy to two-face and batman into a recluse, just imagine what would have happened to the city if they knew of Harvy's crimes right away. The other big thing about him was that he really couldn't be beaten no matter what you do to him. Bane was an absolute power house that was driven, and he managed to put batman down. Bane would have accomplished the most of the three if the bomb was never dragged off over sea, but leading up to that he did accomplish the most. In the end, I guess I would have to side with Ra's the most, joker second, and bane third. LOVE THE TRILOGY!
To conquer fear, you must become fear. You must bask in the fear of other men. Ra's al Ghul