I ate several times at the Essen restaurant on Lindanallee right downtown, near the train station.
Its a slightly upscale place, with glass mugs for pop/soda, nicer looking tables and chairs and a "Happy" feeling environment.
The burgers and fries are good, they have a variety of options and you can add fries and a drink as a combo. They have a vegetarian option as well.
Its counter order and sit down, so fast food style, with better quality food. The Classic combo meal I had was around 13 Euros. There is a chicken sandwich as well but the food is limited to sandwiches.
Overall worth a try. read more