Chowhounds that live in California are lucky that they can buy FRESH dates in the fall and early winter. These are ambrosial! I've found them to be of the barhi variety at farmers' markets. I've never seen them in a grocery store. The farmers come from central to southern CA. Fresh dates are sold on the stem, with 20-30 tan dates attached to each stem. You buy them when they are not quite ripe, let them sit on plates exposed to sun, and they ripen from opaque to translucent dark brown. At that point, they are dripping sugar and yield to a slight pull of your fingers. Then you plop the sun warmed date into your mouth! Sometimes, the pit will stay on the stem and you have an instant pitted date. Be careful not to buy fresh dates so under ripe that they are unable to mature as nature intended. The best are starting to soften and not rock hard.
As to dried dates, they are available in all different varieties. We mainly see the medjools in grociery stores, however, dates abound in different degrees of sweetness, moisture, size, and color (ranging from honey brown to black). I find that 1-2 pounds of jumbo medjools, each date packed in its own paper cradle, make fine gifts for many occasions. It's convenient to keep a few boxes in the refrigerator for gifts. If you keep them at room temperature, they will develop sugar crystals in several months. While perfectly edible, they lose their aesthetic appeal. I've found that mail order is the best source for a large variety of dates. I've been ordering from Imperial Date Gardens for several years. They tend to have good stock and don't run low during the holidays (see link below).
A couple of interesting date facts: by weight,they are a better source of potassium than bananas; they are good sources of naturally occuring sugars - nature's unbranded power bar and far more delectable.