Depending where you stay ?! But here comes few hints for each part of the city:
Pelourinho (Historical Center): Dinha (typical bahian food)
Barra: Barravento , superb view to the ocean and the beach or much cheaper and better Carangeju do Sergipe other side of the road.
Rio Vermelho: Hundres of choices... Cool and Inexpensive and very local: Mercusul da Gama
Fogo do Chao Churrascaria, good and expensive Brazilian Meat House...