There is so much you can do while staying in Berlin. It depends on your interests.

So besides museums there is a bunch of sights one should have seen at least once in a lifetime. Such as the Reichstag or the "Fernsehturm" or the "Weltzeituhr" So I'd advice you check out the bus no. 100 and drive around. you will see most of the important things

afterwards depending on your intrest check out some museums, the east side gallery and of course the bars in friedrichshain.

If you are looking for night entertainment I'd recommend the sage club on thursdays, Magnet on Tuesdays and Duncker almost every day.

Hope this helps.

Have a good time here.

greets

crappo  Thanks a lot for that comment.

Are there any bars or restaurants I must not miss?
Do you know a really cool place to hang out on Sunday afternoons?