Photo by myself on Fifth Avenue, around 21st Street.
The double-decker tour bus point of view is always a cool one, since you're removed from the distractions and mayhem of the sidewalk. You can get a better sense of the architecture of each neighborhood from this vantage point.
Lower Fifth Avenue, between 23rd Street and Washington Square Park, is a favorite spot of mine. There are some beautiful buildings there and great clothing stores, too.
For those who dislike tour buses, take the M5 New York City bus, which starts on the Upper West Side. It travels down Fifth Avenue and winds up in the Village. Northbound, the bus runs on Sixth Avenue up to Central Park, then turns west to head uptown.
Related posts: What Goes Around Comes Around, What's Cooking in Curry Hill and On Hotels and Hype, on Fifth Avenue and Beyond.