For those of you who live in Fort Greene or Clinton Hill, The Greene Grape is probably already familiar to you. However, even if you don't live nearby, I think it's worth a trek from elsewhere in the city. Their provisions store has a good selection of organic produce, fancy packaged foods (many from Brooklyn), and one of the better cheese selections I have seen in the area. My particular favorite so far is toma della rocca, an excellent goat, sheep, and cow's milk cheese that is runny and soft and has just enough tang to make it interesting. The Greene Grape also has a wonderful meat counter, and all of the employees are extremely helpful. Ari and I bought some ground beef from them the other night to make hamburgers, and they were quite delicious if I do say so myself, even though they were made on the stove instead of the grill. The meat and fish is also all organic, and locally raised when possible.
Luckily, they also have a wine store by the same name just down the street. Though small in size, they have a great selection of wines in many price ranges. One of my favorites over the summer was the 2010 Laurent Micquel Syrah Rosé, affordable at $9.50 while also being a lovely, dry summery wine. They also have have hard-to-find Aperol, one of my favorite spirits from Italy (particularly when mixed with prosecco over ice to make a Spritz). In addition to a great wine selection, they have tastings at least once a week, and the last time I was there they had a bottle open for people to taste for themselves.
I love the informal atmosphere of both of their stores, but the people that work there are always ready and willing to help if you need it. You could easily buy ingredients for an entire dinner there, but my favorite is to ask for a cheese recommendation, grab a baguette (and some wine, in a paper bag of course), and picnic in Fort Greene Park a few blocks away. Doesn't get much better than that.