Yeah, I agree on Luna Lovegood. Although she can't conclusively be said to have AS until JK Rowling says so, there's really very little say she doesn't. Unconventional thought patterns, obsession with her father's ideas and conspiracy theories, bluntly stating the truth, unusual style of dress, generally not caring what people say or think about her... all those signs and more point to it.
Oh, and Bill the Cat, definitely.