Meat, potatoes, and watery soup may still be the staple of local cuisine in Riga, but increasing openness in the last few years have brought more variety to the dining scene, so that between genuine sushi bars and real ethnic establishments there are also weaker attempts at exoticism, and prices aren't quiew so low as you might expect in Eastern Europe. Tipping has become more expected, and 10% is the norm for good service.
There is no one specific area for eating out in Riga, although there are quite a few good restaurants around the old town, and many of the larger hotels such as the Radisson SAS Daugava have restaurants that are highly regarded within the city, and there are plenty of choices.