If you're looking for a brand that makes gorgeous, bust-friendly clothing, you'd do well to check out Polish brand BiuBiu. I've bought many items from them in the past and have never been disappointed. They pay close attention to providing an excellent fit for ladies whose boobs don't easily fit into high street clothing and stock a wide range of tops, shirts, dresses, and even jackets.
Some time ago I bought the BiuBiu Gotham top (£19.35):
Image courtesy of BiuBiu