I nominate Akainu. The guy receive way too much credit. A standard villain like him being a finalist in the mangaawards ... Basically, he is just a brute who happenned to be strong enough to kill an important character. I find him uninteresting & I do believe that Do Flamingo, BB, Big Mam, ... are more interesting characters.
NB: the title in the opening post is "fav Male Character" instead of most overrated.
I suuport the nomination of Akainu, for all the reasons stated by zellogan.
hm.. This might be way to early but I will nominate Big Mom, 'cause I can't think of anyone else. For a Yonkou her character seems disappointing. I don't expect her to be high-tier material. Even though she hasn't been properly introduced to the story yet, I believe she will not live up to her status.
I would nominate Blackbeard.
His intellect is way too overrated, especially that I see him as just a coward oportunist.
Sengoku. He was so calm and poised throughout the series so you just knew when he finally fought it was gonna be epic. When eventually did see him fight his composure was long gone and his abilities were a bit disappointing.
I'll also vote for Sengoku. For reasons stated above.
I'd nominate Shiki if that's ok. He was mentioned in ID and took a bigger part in chapter 0, which is canon. His strenght was supposed to be comparable to the likes of Garp, Roger, Sengoku... well, it was not.
after all the bragging, turned out he was just a frog in a well
Sengoku was a dissapointment. You'd think such a high tier person would be more awesome, but he wasn't.
I so enjoy this category. Will update later with more posts.