I can't think of any brands because it's been so long since I actually bought a salad dressing over the counter. I would make your own, because it's cheaper in the long run and a hell of a lot better for your health. I enjoy:
-Balsamic Vinegar
-Apple Cider Vinegar
-Extra Virgin Olive Oil
-Mustards
-Raw Honey
-Hot Sauce
-Chopped raw Garlic
-Dozens of Spices such as Peppercorn, Basil, Parsley, Cilantro, Oregano, Garlic, Paprika, etc...
I always buy Organic, No-preservative ingredients, and make my own dressings from this list, and there are many more things you can use as well. Honey-Mustard is my favorite, but there is also a nice ranch dressing that is a favorite in my home: http://thevegan8.com/2014/05/09/vegan-ranch-potato-salad/
Hope this helps! Sorry it's not a store bought product, but buying at least 4 of these ingredients and working with some spices you may have lying around is going to last longer and be a lot cheaper in the long run. If you find anything, it will probably be an uncommon brand at a health food store, or a farmer's market. Good luck!