If you're tired of being a tourist in Athens, have a meal at Dioskouri. The food is a very good though unpretentious version of the world famous Greek cuisine, served by friendly and efficient waiters. At first glance the place does not strike with elegance, but it's enough to just look carefully at some details - the clock on the wall, for example. And the presense of so many young people (prevalently local) is enough to prove that this is not your tourist trap.
Favorite Dish: My mum loved the chocolate cake with icecream, but, take my advice - a light panacota is much better after the Christmas/New Year excess.