Flour, I'm not sure it's all organic but I do like the stuff from the localish Leatheringsett watermill (and their outlets).

Jos, I can't know how the machine compares to traditionally home baked loaves (have tried a couple but not say your regular white or whatever loaf) but do believe that it can be easy to better a shop bought (and I'm not just thinking Mothers Pride or whatever cheap sliced loaf) loaf with one.