We asked a local shop keeper for a suggestion for good fish in Florence and he suggested Trattoria Roberto's so we checked it out. It is indeed a restaurant for locals, and that means that it is good. The selection of whole fish was brought to the table and you were able to choose which one you wanted. Needless to say it was grilled to perfection and the price was right as well.
We also had pasta and dessert, both excellant. The waiter was very friendly and helpful and Roberto comes out from the kitchen to say hello and make sure that all of his customers are happy. We told him how much we enjoyed his dinner and as we were leaving he gave us a calendar as a souvenier, which was really very kind of him.
You have to go down quit far on Trip Advisor to find this restaurant but that is because it is truly 'local', not touristy at all. We wrote about the restaurant in the guest book at our hotel and the next morning 4 other visitors were raving about "Roberto's" and so greatful to us for having suggested it. Try it - you'll like it.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.