1) Zoro - he's always a badass, but the highlight of his "badassery" was this.
2) Dragon - peoples reactions when they learn dragon is luffy's dad say it all.
3) Crocodile - his outfit screams badass
4) Shanks - stopped the war by himself, Akainu and Blackbeard who had 2 DFs scared to fight him
5) Mihawk - cut a wall of ice in half BY ACCIDENT! He also has an eye for true potential.
This is just my opinion, feel free to share yours.