I like Mountain Mist Quilt Light, which is a polyester batt. I'm also very fond of Mountain Mist Blue Ribbon cotton, and just used and liked Hobbs Polydown, another polyester batting.
On my next quilt, I'm going to try wool. I've heard lots of good things about it.
Janet
PS... It might not be the batting...you might check how tight the sandwich is. If it's too tight it will be harder to quilt. And try a new needle - I had one quilt that was hard to quilt, so I switched to a smaller needle. That helped a lot. And quilting on the bias is much easier than quilting on the straight of grain.