This caught my eye because they look creepily animated. That's a nifty trick. C'mon! Post the last cosplay you liked here!
I generally really don't like SPN cosplays. I'm not precisely sure why, but a lot of them feel more about the cosplayers than the franchise, and I'm in it for the franchise. This pic, though, I think is really pretty cool. I like their attention to detail, good props, and interesting choice of location.
Very creative cosplayers—if you check her gallery, there's a whole lot more.