The Berlin Youth Hostel (this is the official DJH/IYH hostel at Kluckstraße 3)
It's a really large, very institutional building, which houses lots of people in accommodations ranging from small rooms to dorms. The hostel is about four blocks from the Kurfürstenstraße U-Bahn station. It's an easy walk past Woolworths, and a thrift-style store and the headquarters of Der Tagespeigel. You pass a small park before turning north on Kluckstrasse, just south of the Tiergarten. You enter and are facing a large reception desk. You check in, they have you pick up sheets and go up to a room. Ours (my daughter and I) had two bunk beds (one with a trundle), all women. The men had a similar set up on the same hall. There are two large communal bathrooms and the rooms have large, locking cabinets (with keys you can take with you).
We got there, locked our stuff in the cupboards, and headed downstairs. Downstairs, on the main level, there is a large snack bar area, where you can get something to eat when they are open, a bank of vending machines (candy, ice cream, soda, water) where you can get something when they are not open. There are a number of tables and chairs, and some sofas for just lounging. Out the back, behind the building, is a large grassy yard where an international soccer game was going on, a complex of recycling containers, as well as some tables and benches. Inside there are also a bank of three coin phones, a water fountain, and a couple of PCs set up for internet access.
On the far side of the room is a large cafeteria, where breakfast is served. They serve the standard German breakfast, Brötchen and bread, sliced meats and cheeses, müseli or corn flakes with milk and quark, coffee, tea, cocoa, juice. This is a very clean and safe place to stay, and was great for a family.