Germany doesn't have many large supermarkets like in other countries. Here is a list of the biggest shops in the Bonn area.
is a chain of small to medium sized grocery stores and supermarkets/ superstores stocking not only food items but also clothing, electrical goods, housewares, gardening supplies, etc. Bad Godesberg: Michael Platz. Always plenty of parking under the store.
In Sankt Augustin is a large superstore with food, electrical goods, housewares etc. It is part of a mini-mall (The “HUMA” centre) with other smaller shops and stalls selling a variety of goods. “Saturn” electrical store is also located there. “HUMA Einkaufspark”, Rathausallee 16, 53757 Sankt Augustin.
Metro is a kind of wholesalers' club. You will need to get a membership through your place of employment. You can buy most of the standard groceries and household items as well as bulk items like large bags of shredded cheddar cheese or huge packages of meat. There are two in the area - one in St. Augustine and one by the Ikea in Cologne-Godorf
A chain of larger supermarkets throughout the Bonn area with a wide variety of foods including fresh cheese, meat, fish and vegetable counters as well as an in-house bakery. Few stores: Bad Godesberg/Mehlem (Drachenburg Str: 14); Sankt Augustin; Bad-Honnef.
In Berkum and in Bonn-Endenich is a very large and new US, Canada style grocery store with plentiful parking. They also have small appliances, household goods, etc.