I will agree wholeheartedly about Galileo, Kinkead's, any Ruth's Chris, and will add Citronelle, Colvin Run Tavern, and I Ricchi to the list of DC disappointments. I think that sometimes a restaurant gets a reputation for excellence, and then despite obvious drops in service and food quality everyone is afraid to say that the emperor has no clothes. But then one reviewer dares utter the truth, and suddenly everyone comes out of the woodwork to say what an awful place such-and-such has become.
I will use reviews and reputation to help me select new restaurants to try, but I then judge them by (as much as possible) impartial standards. And I'll generally give anyplace one bad meal, chalking it up to luck of the draw. Two bad meals, though, and it's all over. There are enough wonderful places out there that there's no need to keep patronizing proven losers.