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.
My favorite place on Bedford Avenue, this bookstore has both new and used titles. If you're patient and look close enough, you can usually find a book that's worth more than they're asking. Not to mention their stellar selection of magazine titles. Good for design, art, photography, sociology, fiction, and everything in between.