We like this Hamburger Steak house chain. Hamburger means in this case coming from Hamburg.
You get good quality for an acceptable price (not cheap) with nice service and a constantly good performance. If they cook the meat wrong, please tell them, and they will do it again for you!
I recommend to order from the middle section of the menu. You get a good salad, a garlic bread, meat as you order, and a baked potato with delicious sour cream. Ask them for the good (and free) steak sauce and you a get an extra Sour Cream too.
Block House is also in some other German cities and even in Madrid we found one.