The Chelsea Market is filled with great restaurants and speciality food stores and pop up shops. I love stopping in and getting a gourmet grilled cheese from Lucy's Whey or a healthy juice from raw food restaurant One Lucky Duck, while shopping for dinner ingredients at the Italian market Buon Italia. For a great sit down restaurant, I love The Green Table, which serves great farm to table food.
Manhattan's Chinatown is my second favorite neighborhood next to Fort Greene. It's full of people, odors, bars, clubs, cafes, and restaurants. There's always something going on here.