I personally live in Sitio de Calahonda, in Mijas Costa, near La Cala de Mijas and Marbella. Lots of expats and business near with english speaking staff. I moved from Madrid some years ago and in my personal experience, this area was my perfect decision.
As I know all Costa del Sol areas, Yunquera is a beautiful and quiet place to live near "Parque Natural Sierra de las Nieves", if you are a "Nature lover", for sure you will enjoy this place.
Casares is also a beautiful area, has the best of the beach and inland near Estepona. Check out the page I added before for more information. There are also lots of New Developments in Casares in case you want to live near the nature or beach but will all the comfort of new build homes. If you want something more authentic and cheaper check for resales properties, sure you'll find something affordable.