my fallback in the center is U Provaznice http://www.uprovaznice.cz/ good Czech food, decent prices and the service is usually good, also menus in many languages :) but I am the "lowbrow" one around here :) simple and good and I don't really go for the uber frou frou places :) Near the National Theatre there is http://www.universalrestaurant.cz/?page_id=8 which is lovely great soups and fish