Tuesday's lunch hour tip is the amazing Berlin Philarmonic. A short-duration concert (around an hour) happens every Tuesday at 13h, for free. People make the Philarmonie's foyer full, sitting on the stairs, on the ground and everywhere around. Little advice: bring with you a little cushion for more comfort and try to arrive early to find the good spots.
Just an amazing cup of cappuccino. Try the Franzbrötchen with it for a basic breakfast. It's a place for someone who appreciates good coffee done with extreme care.
My favorite lake to visit during the warmest months. It's located in the southwestern part of Berlin and it's reacheable by public transportation, just around 40min from the city center.