I had stayed at the Alex last year so knew what I was getting for not a lot of money. I was there last weekend and the room was at the back ( No.7) and had a private courtyard where my friend's room No. 8 opened onto. Rooms are clean, beds are comfortable, you get free Wi-Fi, free breakfast and the shower is great.
3 stops on the M4 tram from Alexanderplatz and a great base to explore Berlin.
Nice café at the end of the road for a beer and pastry after a day exploring this fabulous city.