If your quilt is being made for a child or is likely to get a lot of heavy use, something like Quilter's Dream Poly works very well. I have recently fallen in love with cotton batting. I know that it is a little pricey, but I have found some of the other brands that Hancock's and Joanne's sell to be difficult to work with as well as having a rather stiff feel to them, but that is a personal opinion. It also comes down to what resources you have in your area and what you are willing to spend.

I agree with ghostrider do some reading frist beveryone bincluding me but I've learned to read before making a decision

Mighty good info here...love this board!

warm and natural and
warm and white your quilting can be farther apart less quilting the other batting's you have to quilt as close as 2" to 4" apart a lot more quilting

Quilters Dream Blend Batting for me. Supposedly it is made for machine quilting and you can stitch up to 12" apart. Even though it is a 70/30 blend it still gives you that crinkly look when washed.

I usually use Warm and White.

Which ever brand of batting fits my budget. I like to try diffrent battings, when I can get them on sale but have found I like 80/20 the best. I FMQ and it isn't too heavy to move easily aaround on my sewing machine.

I don't think JoAnn's sells anything better than Warm & Natural. This is very good. very good for showing the quilting. Quilts well and as the name implies, Warm.

I also like Quilters Dream, not available at JoAnn's. It is lighter weight and softer, makes quilting a little flatter and less noticeable.
peace

Ditto

I like 80/20 batting by Hargrave.