I would say ninja. The reason why I say that is they were sort a a working mans samurai. They trained from the time they were little to be consumate warriors. They were the fierciest of the fierce and a precursor to modern day special forces. Samurias while enjoyijng a nice hollywood image were often cruel to peasant class. And remember samurais served a master and they wre no more virtuos than the ones they worked for. Ninjas were not a fuedal birth right but something a man or woman could work for.