My first trip to Berlin brought me to the border of Kreuzberg and Treptonw for a Love Parade pre-party. That was in the huge Arena hall (not to be confused with the small techno club in the same location), an old factory complex that is also home of a lot of artists workshops and the famous Badeschiff (swimming pool ship) in the Spree river.
But around the corner, hidden along the canal, you ca find numerous small pubs and clubs. Club der Visionäre is one of the most popular ones. During the day ideal to relax a bit, especially if the sun shines. In the evening hours an excellent place for some food. And in the nighttime a breeding place for electronic music, of course without closing hours. It can be ferociously crowded, especially on sunny days. The neighbours of Freischwimmer are slightly less noisy and just as relaxed.