Sarah Woodruff from "The French Lieutenant's Woman", which is coincidentally one of my all time favorite novels. I love that she is such a proto-feminist, not afraid to be who she is at a time (Victorian England) when women weren't allowed to be anything other than wives or domestics. I also like that her motives are not necessarily the obvious ones, and that she works from an agenda that's all her own and difficult to decipher, even after having read the book several times.