For my wedding a year ago I searched for a caterer with reliable service and decent prices--and good food, of course. I found what I was looking for at Twomike's Catering. They are based in St. Louis but willing to come out to the O'Fallon area.
We had a brunch buffet reception and wanted to keep the food simple but elegant. Twomike's served excellent chicken salad croissants, scrambled egg casserole, and fruit along with juice and coffee. Their homemade food, like the scrambled eggs, was very tasty. We had mini quiches which I think were bought from a store, and weren't quite as outstanding.
Their service was good, and they were clear about what they would provide and when. When we went to a preliminary tasting I found them very friendly and helpful. Above all the prices were very good, better than we found anywhere for the quality we wanted.