Everyone is thinking them, so here they are:
Posters who make themselves prominent by posting blatant junk.
Posts giving blatanly chauvanistic and shallow advice or boasts.
Unregistered User with no name or identity bringing up old and disliked by the majority threads, or posting inflammatory comments without rhyme or reason.
And, deleted posts don't disappear entirely, and the edited text at the bottom of the post is too big