Sveta: Cheap, good quality foods, in wide selection. Make sure you check the package integrity first - people tend to open boxes, make sure nothing is missing.
Sveta: Very questionable looking place (the building needs renovation immediately), service is good, wines and food is quite good too. About the only open place on weekends and holidays.
Sveta: Central square. If you intend to visit the tower: the queue is 40 minutes or more, but there's souvenirs wending machine to keep you entertained.