Cosmoveda is a hidden xberg gem. It's an Ayurvedic supermaket that happens to come with a kitchen with it. There you can find a delicious Ayurvedic lunch menu (with soup, main and a little dessert) in 3 different sizes, prices starting at just 5,90. Not to mention you can shop the ingredients that you just ate in case you want to try to cook Ayurvedic yourself.
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.
Peres Projects mostly showcases young, emerging artists and is at the forefront of fusing art with fashion, celebrity and the love of a good party, which seems to work very well in Berlin. Having recently moved into an ex-Soviet building on Karl Marx Allee, the giant new space contrasts brilliantly with the commanding facade.