My favorite batting is Mountain Mist Blue Ribbon 100% cotton, but this is a very traditional batting and not for everyone. I like it because it gets softer with every washing. Antique quilts were made with this type of batting -- no needlepunching, no scrim, no polyester. I hand quilted this exactly once; there are better battings for hand quilting, believe me! It is great for machine quilting, though.
My second favorite is Hobbs 80/20. It is a little puffier than the MMBR and is good for hand quilting as well as machine quilting.
I used to use Warm & Natural, but the needlepunching through scrim gives it a slightly stiffer drape that I don't like.