The best cheeseburger in Berlin costs less than 5. Burgermeister is mandatory in town when you're craving for a basic and delicious to the bits chesseburger. 

My favourite book store with a minimal interior and maximum range of books on architecture, design, art, philosophy and politics. 

Best record store in Berlin. A great selection of Rock, Folk, Indie, Wave, Industrial and especially the huge floor dedicated to House and Techno Records. Staff are typical Berlin-Style - not very friendly but very knowledgeable.

Kw is a great art institute situated at the backyard of a very eastern part of town, place for many other small galleries. Auguststrasse is worth the walk and Kw is worth the stop.

A place where I spend some time almost everyday is the Marheineke Markthalle on Bergmannstraße in Kreuzberg. It's just around the corner from where I live and a great place to buy fresh food and products from local farmers or all kinds of delicatessen from different countries. Many market stalls also sell freshly prepared food and it's always busy at lunchtime. For saturday mornings try the original french croissants.