I lived in Berlin for a year, but it's been a while (2003-04) so I'm not sure any of the places I can recommend are still the way they were back then. I know I've had some fun nights in Ausland and Weinerei. Pergamon Museum and the other museums on the Museum Insel were fascinating, and Hamburger Bahnhof had a great collection of modern art. There are so many exhibitions, festivals and events going on in Berlin at all times, with both new and established names, so the best advice I can give is really to buy a copy of Zitty when you get there and read about the events of the week.