Beyonce, 17 years in the business and still performing and in some cases outperforming the newer faces of pop, but as an established artist she can make her albums focus on music for the fans rather than casual audiences.
I also like Katy Perry and Rihanna, and hopefully if they keep going the way they are they can bring out a more artistic record in the future. Rihanna did that with Rated R and so she is capable of it and Katy is slowly developing maturity into her records.
I know it's somewhat fashionable to moan about modern music but I really like the current set of female stars.