Most obvious candidates have already been mentioned, so I'd go with the most recent ones which are rather occasionally overrated, than overall.
- Hancock
For some reason she's top tier, while all she has done is destroying Pacifista with ease, a feat Post- time skip Sabaody Sanji accomplished, being portrayed to be superior to Momonga, a character being part of a group which has been constantly used as hype tools for high tiers and above
and she's proven to be capable of using all 3 haki types with being implied to be an advanced haki user (barrier type at the very least) due to ther sisters feats....Everything above applies to Katakuri, but on top he's a awakened devil fruit user and proven to be a decent CoA user and a lot more versatile as well, yet he's not a top tier...
- Katakuri
Apparently he's stronger than every other Yc1, being compared to an old legend as Rayleigh and capable of soloing even various combinations of two high tiers.
- Enel
Sometimes underrated and downgraded to New World fodder, but currently overrated due to being compared to mid high tiers and decleared as capable of one shotting most decent new world fighters, like mid tiers and above (ark maxim buff not included)...This quote is literally made for Enel lmfao
Best you could likely say is that Enel is probably a slightly better version of Caesar, which is definitely not New World fodder, but neither close to the upper echelon.