Normally I don´t recommend shops, frankly there is a huge competition everywhere, but this one is a very special shop and you shouldn´t miss at least a short look.
When we came out of the Kolumba (another very interesting museum and church) it was raining and we noticed this shop just across the street. This chain is well known in Germany for many things of the daily use, food, housewares, cosmetics, leather, cloth, furnitures, nearly everything you can imagine, in a very high quality, sometimes handmade or produced in traditional German handicraft business and sometimes a little old fashioned or retro. But of course the items come at a price!
If you want to buy some gifts or any German stuff, but not the typical souvenirs, this might be a good chance to make some very special purchases.
There is a kind of bistro in the shop too, where you can try and enjoy some of those specialities.