Cotton batting is typically lower loft. I *love* cotton batting because it gets softer with every washing. My favorite battings are Mountain Mist Blue Ribbon 100% cotton (very traditional flat batting that "crinkles" when you wash it -- this type is what antique quilts were made with) and Hobbs 80/20.
From what I have seen, Hobbs is a better brand of 80/20 than others. It has a little more loft than the Mountain Mist, and is good for both machine and hand quilting.