Conveniently accessible from the Hermannplatz subway station, Karstadt department store and…read morePerfetto supermarket are one-stop shops to complete most, if not all, your shopping needs of the week.
Karstadt carries almost everything, like school supplies, clothing, books, cosmetics, and plenty of chocolate. For the most part, staff is friendlier than other stores I've shopped.
Perfetto grocery store is one of the better ones I've been to in Berlin, and it's fit my needs. Although, their produce isn't always the best quality, and it has the tendency to be more expensive than outdoor markets. It's pretty much a basic grocery store that's stocked with cheeses, meats, coffee, frozen foods, and yes -- a chocolate section which also has sugar free choices. In addition, there's a small bakery, butcher salad counter that's surrounded with assorted cheeses. On occasion, free samples of salads are offered, and they are delicious (and pricey).
It may not be comparable to the all-in-one super stores in The States, but the offerings in both department and market are good enough. It sure beats having to dash to several different stores.