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.

Soluna bakery is where I get my (delicious) bread.

Situated in the patio of the Kunst-Werke, a well established exhibition house for contemporary art, this cafe features mirror-walls and a selection of nice cakes and lunch menu. 

It is the highest place in Berlin and is made of wartrash. Translated Teufelsberg means "Devils Mountain". The whole area always reminds on how beautiful Berlin is: On one side you see the big city and when you turn around pitch black forrest.

Wim Wenders shot Wings of Desire here. It's a quiet place to work and definitely a gorgeous place to visit. Combine it with a visit to the Philharmonic, just across the street. Affiliation is 30 euros per year and you have lots of desks all over the library to choose from.