For the last two centuries, a Fifth Avenue address has signified social position, prosperity and respectability. Whether around its lower reaches on Washington Square or far uptown around the Harlem River, the street has been the home to Manhattan's finest mansions, hotels, churches and stores. Between 42nd and 59th streets, Fifth Avenue has always drawn crowds - particularly during Christmas, when department-store windows are filled with elaborate displays - to gaze at what has become the automatic image of wealth and opulence, or to visit Rockefeller Center, Radio City Music Hall or the Museum of Modern Art .