I really love Quilter's World magazine, which is an online magazine. It is full of projects, and the directions are very well organized and easy to follow. I think it might even be free to subscribe(?) Here is the website. See for yourself:
http://www.quilters-world.com/newsletters.php?key=QQQN
As for the others, I think it depends on what kind of quilts you like. Some of the magazines are geared more toward art quilts. Most of them feature certain fabric lines and encourage you to purchase those lines or kits. I think my least favorite is Fons & Porters. But the others are all good, IMHO.