If you love live theater, book yourself some tickets for a play at Berliner Kriminaltheater. Look online for times and prices.
If you're spending a while in Friedrichshain-Kreuzberg, Berliner Kriminaltheater is an interesting place to start your exploring. This arts and culture attraction is one of many attractions worth seeing here. Alexanderplatz, Brandenburg Gate, and Reichstag Building are also ready to be explored nearby.