When I go to a restaurant, it's a place that caters to locals and is recommended to me by a local.
I don't go to restaurants that are listed in a guidebook. Even if they were good when the recommendation was first printed, the listing changes the place. They get a new tourist customer base then change their menu, and service, to suit the new customers (who want to know why they don't serve hamburgers, put more ice in the soda, serve Budweiser, have catsup for the fries, bring the tab after delivering the food, etc.).
In Scandinavia, my destination this year, I plan to eat sausages from street vendors and picnic from grocery stores. I'll probably have smorabrod sandwiches from a corner shop too, but it will be one that has a line of locals rather than tourists.