Dan and Roseanne's hair in season 2
Lol has to be the worst hair they had in the entire series, Roseanne with the really short bowl cut making her face and head look even rounder and fatter than normal, and Dan with that long curly mop hanging over his ears looking in desperate need of a haircut.
Although Roseanne's ugly butch mullet in the beginning of season 3 is bad but she only has it for like 2 episodes though.