Red and Green

It looks like Harley Quinn and Poison Ivy are ready for a night on the town.

Steampunk Corset

I know this is not a great costume, but she looks pretty good in it.

Altered Villains

On some level these are not costumes, but fashions inspired by Gotham Villains. I still think it is pretty cool.

Sexy Catwoman

Is the whole point of Cat Woman cosplay to see how sexy you can be? That might be it