Berlin is amazing eh?! I went last year.
Stumbled into a few clubs one night and found them to be rather crap, came out at 1am, went to an Irish bar, a local Irishman told us we needed to go to the real clubs which the tourists don't go to, took a taxi 20 minute drive into an industrial area which looked like a building site and found what looked like a giant red bricked bread factory in the middle of no where and clubbed till 9am the next morning. Apparently it opens at 9pm on the Friday night and closes at 9am on the Morning, who needs sleep?
Next night we went to a club in a sky scraper which had blacked out windows, danced till 6am when the windows were opened 20 stories high and watched the sunset with tiesto playing in the background. Amazing weekend I'll never forget, sight seeing like yourself was also fun