Kinda hard to chose. I'd like to say that both P1, Scar and Wolf were the best. P1 because he was simply a badass kicker and he did not hide behind too many weapons like Wolf did. Wolf was an asskicker too, but he hide behind a lot of weapons, so cool or not, I consider it cowardly to hide behind that many weapons. He was still cool though. Scar was cool too although seemingly being a youngblood but I think he was cool because he managed to stay alive much longer than his friends and he also proved that yautjas are more than just bloodthirsty mindless monsters as he managed to befriend Lex. By befriending her he also proved that yautjas are more than bloodthirsty monsters. They actually do know how to feel and think beyond their bloodlust.
So, still being a little unsure about who to chose I think I will go with Scar as being the best. But if I can only chose upon their fighting style then I chose P1. Again Wolf was cool but he was hiding behind too many weapons (which is still cowardly in my eyes)