I'd imagine it has something to do with two excellent schools in Henry Cavendish and Ravenstone, good pubs (inc. The Bedford for its comedy, and The Clarence, Grove) and restaurants (Harrison's, Lamberts, Gazette), lovely cafes and bakeries (Trinity Store, Milk), a Bikram
Yoga centre, Aveda spas, good leisure centre and now Movers & Shapers gym. Our GP is excellent, as is the Balham Health Centre for walk-in emergencies. The library is also good. Being between the commons is also a huge plus as is access to the northern line and overground to Victoria, Gatwick...
Oh, and the fact we are all lovely