Quilter's Newsletter, Modern Quilts Unlimited, Machine Quilting Unlimited (even though I don't have a longarm, they have stuff for DSM's too), and Quilting Arts are my favorites. I tend to pick up random subscriptions when I see them cheap, so I think I'm also getting McCall's, AQS, and one or two others. I can't keep track though, since so many of them are dying off. That's made some of my subscriptions get lengthened out to several years after 2-3 magazines died and sold my subscription to magazines I already have - I think I'll be getting Quilter's Newsletter for the next 4 years before I have to pay again now, LOL.
I also get the sister magazine to Quilting Art - Cloth Paper Scissors and I enjoy that one a lot too. It's not a quilting magazine per se but if you do art quilts there are techniques and ideas that could transfer over.