I usually think of the cruciferous vegetables as being the easiest way to get sulfates in a healthy diet. Also garlic, onion, milk, cheese, eggs, & meats. You could actually get it by taking glucosamine sulfate as well.
Oh I almost forgot, the fun way to get it. Soak your feet in warm / hot water + epsom salts because you can take it in through your skin that way. Or a bath if that sounds fun.