Croesus
Adventurer
Depending on the product, most comic stores also sell magazine storage boxes, which are heavier duty than the general purpose boxes at staples, and stack very well. You're hopefully using these for any Dragon/Dungeon issues you have, and paperback products might fit as well. I think the hardcovers are too large, alas.
These are what I use and they work great (mostly). I stack them two high with no issues, three high would probably be okay, tho a box of just magazines might be too heavy to go on top. They are cardboard, so provide minimal protection from water, fire, and other such hazards.
One issue is that box sets tend to be just a hair too wide for these - literally less than one inch, but still too wide to fit without crushing/bending.