What was your favorite or most unique costume you saw at your midnight showing?

Someone was dressed as Harrys Patronus :)

I dressed up as Bellatrix, but probably the awesomest costume I was was this lady walking around dressed like Umbridge, who was writing up people for detentions.

I got written up for "Inappropriate Magic Misappropriation", :P

There was someone at the midnight premier dressed as the sorting hat. They had this brown conical material covering their whole body and they'd cut out some holes for their eyes and for the rim they used brown cardboard. It looked quite good. Lots of people dressed up where I went. There were a few death eaters, some dressed as ghosts, a few dementors, some Bellas, at least 1 dumbledore and 1 mad eye moody, lots of school and quidich robes as well as a few cat and dog animagus for Minerva and Sirius respectively. There were also a few Snapes :D