I currently subscribe to Quilting Arts (and have since 2002), American Quilter (the American Quilter's Society magazine that comes with membership), American Patchwork and Quilting (which I will not renew), and Quilters Newsletter (which I'm about to cancel after only 2 issues because they now add 30-page catalogs of non-quilting related merchandise stapled in the center
).
If I could only have one, it would be Quilting Arts, hands down, as art quilts are my primary interest. I don't have any interest in making someone else's pattern, but I am definitely a technique junkie. Second choice would be American Quilter.