One more recommendation - the first season of Kojak (1973-74) was filmed on location in NYC. None of the other seasons were. Although it’s just TV - and much of it is shot on soundstages - this group of episodes gives a good feel for the vibe of the city back then. Kojak himself was a proud ethnically-Greek character and the show often tries to portray how things happen in the city on the ethnic group level, which has always been very important.
Don’t forget “The Seven Ups” which has some great scenes and excellent photography. The car chase is awesome but skips a few sections of the city & suburbs.
ETA: The Chase: http://www.youtube.com/watch?v=9vACWV5sRcY
Another great movie is NY77: The Coolest Year In Hell - NY77: The Coolest Year in Hell (TV Movie 2007) - IMDb
If it was mentioned earlier I apologize =)