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.
I often go exploring into random and dilapidated areas of Berlin. I like the thrill of finding new nooks and crannies with strange visual sites. A few months ago, an old housing colony was abandoned, and many objects (such as couches and front doors) were left at the edge of the city to rot or to be scavenged. This is a view from a non-descript area of the S-bahn train tracks (between Sonnennallee station and Treptower Park station) into the most Southern part of Neukölln district.
One of my favorite magazine stores in Berlin – a wide range of temporary magazines and books and the smell of printed pages. Located in the center of Berlin, it's a must go for all print lovers.
One of the most beautiful pieces of Berlin actually is a piece of another city (Al-Hillah, Iraq). Normally Berliners are laid back and like to hang around, drink beer and chat till sunrise. Sometimes they do get excited though, and then they start taking old war-battered stones and piecing them together to (re)form walls. The results are great as can be seen all over Berlin, but the Ishtar gate in the Pergamon museum is where they’ve really outdone themselves.