Yea Zoro is probably the most consistently badass character in the show. Akainu humbled himself infront of Shanks, also tried all these underhanded tactics to get to people, he's a beast, but he's more of a force than anything.
Lucci is dope, most pure character in the show. He had no other motive but to fight Luffy. He allowed Luffy to follow him, which put the CP9 at risk, but he didn't give a shit he just wanted to fight. Less talking more action with him.
Enel is a pussy.
Crocodile is a mafia boss. Definitely up there.
Shanks is beast because he is so nonchalant, yet is stronger than your fave.
Law has a snarky demeanor when everything is under control he is badass, but he is more of a worrywart than Zoro, which gives Zoro the edge.
Zoro probably is the most badass character, it's a subjective topic, but from an objective point of view he gets the most screentime out of all those characters, and his entire character consists of doing badass things, thus he holds the most feats in that regard.