Marlene, I understand your desire to find unique streets of shopping in NYC (I have always yearned for this myself), but I tend to agree with Angie: Boutique shopping in NYC can be disappointing. I can't tell you how many times I've hunted down some shop I read rave reviews about only to be disappointed when I find it.
If you want to shop (and not just window shop) Soho will maximize your time since it has lots of great shops located very close together. True, there are a lot of chains, but they tend to be bigger or flagship-type shops with a much greater variety than you'd see in their locations anywhere else. And mixed in with the chain shops are a smattering of interesting boutiques.
There are a few streets (Bleecker comes to mind) worth walking down in the West Village. And I've heard that Brooklyn is really the hot place to shop now. The next time I go to NYC I'm headed there just to see what the story is.....
I always make a stop in ABC Carpet and Home on lower Broadway....an interesting amalgam of things for sale and much more than a home furnishings store. (great tapas place inside, too)
Have fun!