For a local flair, I’d recommend to head toTiergarten Quelle under the S Bahn Tiergarten station. There are mainly big tables to be shared among all the guests, the place smells good of food when you enter, the staff is friendly. I’d recommand to book in advance, it’s often packed, thus the waiting time can be quite long, but they also warn you about it usually.
The dishes are enormous, served on big plates, you’ll sure get your belly full. The food is German, so not very light, lots of pork, cabbage, potatoes and of course, beer, it’s said they have very good beer, I can’t confirm since I don’t drink beer. And the good thing is, it’s very cheap!