Tresor is best on a wednesday, also check the new Ostgut/Panorama bar which is now called Berghain, SO 36 on a monday for electric ball room, and also Maria am ostbahnhof... lots of cool bars and underground clubs around Warschauer Strasse/ Frankfurter Alle area (Freidreichshain) too many to list here, also it's the best place for good cheap food, just get U-bahn/S-Bahn Warschauer Str., walk across the bridge and do a right into the streets there heading in the direction of Frankfurter allee U bahn, Boxhagenerplatz is particuarly good for cheap food, check the Meyman Meditteranian resteraunt, and Pizzawerk for pizzas for only 3 euro... Stereo 33 bar is also a good chill place where you can get a beer and listen to some cool tunes...