Salt n Bone - Great place for a casual dinner. Chill atmosphere, friendly staff. Good selection of drinks and spirits. Mixed grill for two is a taste of everything. $$ outside seating In the summer.
Brandenburg Gate - must see in Berlin
Neni Berlin: Israeli food! Super cool atmosphere, it's pretty much a greenhouse. Dishes are meant to be shared; for two people 2 is not enough and 4 dishes is plenty. Great for lunch or dinner, make sure to make reservations and get a window seat for a great view of Berlin. $$
Berghain Club - very hard to get in. Must wear all black, no heels. Don't look fancy. Sunday is their best night. Go Saturday to get stamped which is good for all weekend including Monday. Best nightclub in Berlin. No pictures allowed inside.