Actually, the answer I'd give is: "well, I'm an excellent web designer and developer, and I'd hope I'd be able to contribute significantly to this company using the skills I've developed in that area. If you're talking about non-technical skills, though, I think " <pick a strong interpersonal skill> " is my strongest quality and it really contributes to my success in this position because " <insert explanation relating interpersonal skill to position> "."