Option #1: Angel. Depends on me finding my sequined t-shirt that says "Angel" and an affordable pair of wings. Very low-profile costume.
Option #2: Daria. This one would be a little harder and presumably more expensive -- I'd have to find the green jacket, boots, and a skirt. And then I still might not get recognized.
And now that I have an idea, what am I going to do for Halloween? Any ideas or invitations?