Well Ray I think all of them are important, and one needs to have all three to be truly strong and Courageous. If you have Honor but no Valor or Ambition you may see something you find immoral but be too afraid or lazy to do anything about it. If you have Valor but lack Honor or Ambition you would be brave but never feel like helping anyone or feel they haven't done anything for you so why help. With only Ambition you would act only for yourself and your intentions would likely often be ill.
With all three Honor, Valor, and Ambition you will be truly great. Your Ambition will cause you to act on impulses and with Honor and Valor these impulses will be for a good cause and backed by good intentions. You will be brave and risk yourself to save another, or do the right thing even if it means you will lose out on something.
To be Courageous means you embody Honor (Truth/Justice), Valor (Bravery/Strength), and Ambition (Willingness to take action for what you want/believe in). If you lack even one of these qualities, courage will be only a hollow word when spoken towards you.