Batman: Arkham Knight
This is purely a fashion list. We’re not going by which characterizations of Harley Quinn are the best or worst. The outfit she has on in Batman: Arkham Knight is… fine? It is impractical from a villainy standpoint. White puffy sleeves are going to get messy really easy, for example.
For me, I think it looks more like a “Halloween Sexy Quinn.” It doesn’t have some of the hallmark elements for the character. It really amps up the sex appeal. And, while it does have some of her trademark fashion elements, it sometimes doesn’t really seem like her.