I have used flannel and fleece - both with and without batting/backing. The ones i liked the best were the top with fleece only, and the top with flannel only.
i was looking for a way to make a summer weight quilt. I noticed some in the quilt history exhibit at a quilt show once. The top was made with mens shirts and the combined backing/batting was just one piece of flannel. So i tried it with a top made with new fabrics and the back with flannel i washed in really hot water a few times. I liked the results. I have learned so much by studying old quilts made during the times that life was harder for people cuz they really knew how to think outside of the box because they had to. I admire that.