I have family in New York and we travel there frequently. My children LOVE walking through Chinatown. When doing this, you absolutely must take a walk through a grocery store to look at all the interested seafood! and buy a delicious chinese pastry for your walk.
My children learned early on how to haggle with the street vendors. Even my three year old got into the act and scored a fabulous pair of slippers for $3. It's a great way to spend an afternoon in New York.
It's definitely an interesting neighborhood, but there is quite a bit of walking from the subway. You will find all kinds of interesting food, souvenirs, toys, markets, etc. If you have small children this may not be the easiest or best choice, or be sure to bring a stroller or sling!
If you're into street markets and hawkers, wet seafood markets and exotic fare then this is the place for you! Authentic chinese food and exotic Asian vegetables and fruits abound! There is no shortage of choices!! Its a little bit of a trek by subway from Manhattan but may well be worth it if you're looking for lots of variety!