It's so subjective.
For bed quilts, I love Quilters Dream wool. it is lofty and yet lightweight, and I have arthritis and hate a heavy quilt on me. For kids or modern types who will throw it in the washer and dryer with the sheets, I like to use Hobbs 80/20. it takes a lot of laundering and looks great. I love Quilters Dream cotton select too. It is wonderful to work with on the longarm in Deluxe or Select weights, and I love hand quilting it in request weight.