If your quilt is being made for a child or is likely to get a lot of heavy use, something like Quilter's Dream Poly works very well. I have recently fallen in love with cotton batting. I know that it is a little pricey, but I have found some of the other brands that Hancock's and Joanne's sell to be difficult to work with as well as having a rather stiff feel to them, but that is a personal opinion. It also comes down to what resources you have in your area and what you are willing to spend.