winn (or more to the point the actress) did her job perfectly. you're meant to hate her. not in a love/hate way like dukat. with winn you are just meant to hate her. so i disagree with her being the worst character.
most hated then yes, she wins by a mile.
i agree that ezri was a weak character and was a poor substitute for jadzia.
'Look at you. You're pathetic! A confused child, trying to live up to a legacy left by her predecessors. You're not worthy of the name 'Dax'. I knew Jadzia. She was vital, alive, she owned herself; and you - you don't even know who you are. How dare you presume to help me? You can't even help yourself! - Now get out of here, before I say something unkind.'