I think this costume on the right is what I would wear if I decided to go as Extreme Audrey Niffenegger.
Disney's Enchanted costume and Pikachu
I saw loads of versions of this Watchmen guy; they must have got pretty hot. And some gothic lolita Heathers (although I'm not too good on pinning down names to exact styles, you might have to fill me in).
Okay, that last one is me, unintentionally but perfectly colour-coordinated with Gary's Derek the Sheep book. Lamely, I didn't have any costume in mind, but I'd recently bought some go-go boots off Ebay that turned out to be WAY more plasticky than I was expecting, so I thought, if I coudln't wear them there, I couldn't wear them anywhere. I felt a bit silly walking to the Tube station wearing them, but once I got to Expo, I looked rather drab. But I got about five people who 'recognised' my costume; I wish I'd written down the names they gave me. The only one I can remember was Mad Men so yeah, I'll go with that.