Also Garling and Shamrock designs hitting hard, but the first one is very subjective.
Oh and the hardest hitting design with the most aura imho...Blackbeard for me, and ngl his post timeskip design is so much better now. I am rating it on this still being a pirate manga, so I sense from his design alone that he is meant for higher heights. Those heights that were untouched in the story so far and only foreshadowed through something like a mural or an ancient robot.