Arlong and his merry band of faggots.
Arlong's group has some interesting stuff going on.
They're the only pirates we've seen who engage in statecraft (as opposed to Wapol, who turns to piracy as an alternative to statecraft)
In spite of their brutality and racism, they clearly have a strong nakama bond.
Recent events really help to explain their role in the OP world and justify, to an extent, their anger.
As far as I can tell from doujinshi, the faggotry is primarily reserved for Arlong x Chuu, and given the lack of fishWOMEN at Arlong Park, it may have been a matter of necessity.
I also didn't get the Absalom hate. Perhaps because IMO, he's the most handsome stitched-from-corpses character I know of. Plus, we discover that Sanji is basically just as much a garbage-soul as he is… he'd be just as much a pervert... if he had the power.
Kaku is more overrated than bad; Pasta Machine salvaged him, but I find the fan-love annoying.
The Tennryubito actually succeed, because they do exactly what they're supposed to-- trigger hatred with no compromise or redemption.
Hogback, I suppose, annoyed me in actions the most... not the zombies, not even the creating a puppet girlfriend, but the whole "save my genius" before he gets crushed-- it's so sickeningly cliche.
Personally, I can't stand Ace because he's too pretty. The body type simply does not exist in the OP universe-- only Smoker's body is close. When you can take an Oda character and drop it into any other series and not look distinctive, then it represents a "dropped step" on Oda's part.