I can't think of celebrities I think of who are slightly chubby as well as attractive since I don't much pay attention to celebs. However, there are some amazingly beautiful women on this board who carry a bit of weight that only enhances their beauty.
Edit: Slightly chubby is a highly attractive range from "carries more meat than a normal model" to "a beautiful woman who carries her weight well." in my mind. Maybe I'm less discerning than the average poster.