Some handquilters like Warm and Natural, some don't. I use Mountain Mist lite (a thin polyester batting), Mountain Mist Blue ribbon (cotton) and Hobbs Polydown (polyester). My current quilt uses wool batting, which is also nice.
I get the smallest stitches with the Lite, and it's probably the easiest to quilt. The Hobbs and the wool batting have more poof to it, which I like a lot - it makes it easier to see the quilting design.
You can get batting swatches to try. Harriet Hargrave's quilt shop in Colorado sells 15 inch squares of batting for a few dollars each.
Janet