One of the best things to do in Berlin is going shopping!
“Berliner” people seem to love it and tourists, as well ☺. Since you can see shopping malls everywhere. Even at the main train station Berlin Hauptbahnhof:
For example, one of the most well-known shopping centers in Berlin is Alexa.
One good thing to buy in Berlin is clothing! I highly recommend going to the H&M stores. There are several of them in different shopping malls of the German capital. It is a good idea to go to some of them or to all of them, since they don’t have the same clothes. It has happened to me that there’re pretty shirts in some H&M stores and in another one, there’re other pretty ones but not the same model.
Another nice shopping center is located at Marzahn:
Maybe you are in Berlin and have no more time left and you really wanted to go to Russia, too. Well, you may be interested in shopping Russian nice souvenirs though for yourself, your family, and friends 🙂 I recommend to go to a store called “Aljonka – Russische Spezialitäten”. Here they sell nice Russian stuff directly from Russia and nice quality. You may find from candies & chocolates (the same ones that i saw in Moscow ☺) to Vodka and Matrioshkas.
Finally, are you feeling hungry? If you like fish, i recommend you to go to a Nordsee Restaurant.
I have asked for an “Fischfilet Champignon” (http://www.nordsee.com/de/fischfilet-champignon.html) ^_^.
In Berlin you can take a boat tour in the Spree river. When you are offered to drink something, try the “Berliner Weiße”. There are two colours: green and red. I recommend you to taste the green one. I found it more delicious 😉
Then maybe you want to try a Berliner Bier? ☺
One nice thing you can do is to take nice pictures and even videos of Berlin during your boat trip on the Spree River 😀