It is the connection between Leinestrasse u-Bahn and Tempelofer Feld. The park is wild and quiet, and super relaxing :) it is nice to sit on a bench and do some people-watching: it is a big inspiration for illustrators!
This museum of photography is really great, and the highlight for me after the inspiring exhibitions is the good coffee and great cakes at their coffee place.
I find myself there almost every second week for a drink and a slice of cake. The food is perfect, the ambiance is nice and it's really alive as a lot of people are coming directly from the running exhibition. At the entrance you can find an interesting bookstore and the best photoautomat of the city right outside.
Last but not least, it's only some meters from the Helmut Newton Fondation ( which doesn't have a nice coffee place itself yet ).
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.
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.