In order of where I've bought most over the past few years (although trying to buy nothing this year):
Jigsaw (work suits, coats, dresses, skinny cords, shoes, boots)
Whistles (dresses, scarves, jersey tops, bag)
Anthropologie ( casual jackets, blazer, tops, jewellery, scarves, cotton trousers)
Brora (coat, jumpers, scarf, hat, gloves)
Reiss (coat, two leather jackets)
NYD jeans, Nike and Puma sportswear and trainers from Next Directory (only ever buy non-Next branded). Next day delivery very convenient.
Hobbs (tops for work)
Dorothy Perkins (got some attractive, cheap Summer dresses for hols)
White Stuff (plain tops, Summer trousers, Summer skirts which are probably frumpy but are fine for lazy days on holiday)
Fat face (some Summer casual stuff)