Depends on how you define worst here.
In terms of pathetic - Its Sanji (resorting to lies then whine about Toei), Shanks (shit reading skills - complete denial) and Admirals (they got done by Oda though) Law fans are pretty retarded too but they are so insignificant it doesnt really matter
Yonkos and Luffy fans are so insecure of Zoro and Mihawk (I still find them better than the other three generally, they have some retards like Goofy Top 1 retards)
Zoro fans (has a mix of everything, trolls, based debaters, just appreciate the character, toxic, ready to fight anyone and everyone)
Sanji
Shanks
Admiral
Luffy
Yonko
Zoro
Everybody is a villain to somebody else so there is no universal choice here