Little Maho
Little Maho Bay is a great beach for many different types of people. It's smaller than some of the other beaches, but a little less well known so don't expect it to be overly crowded. It's also a little on the calmer side, so those looking for a churning surf should probably look elsewhere.
There are a number of facilities available for public use at Little Maho from the campground that is onsite. They have restrooms, a restaurant, a small store, phones, and even an activity desk. Rentals are available for snorkeling equipment, kayaks, and windsurfers, and they even offer SCUBA packages, lessons, and equipment.
There's some decent snorkeling to be found, particularly along the sides of the bay where there are lots of rocks. As mentioned, this is a great spot for those that don't have their own snorkeling gear as it can be rented right on the beach.