Dungeon Magazine
Back when First Edition was still the hot shit, TSR decided they could make a few more bucks by taking adventures written by regular gamers and selling them to everyone else. Thus was born Dungeon Magazine, the adventure module counterpart to Dragon's more varied pages of lore.
Dungeon usually ran four or five modules every issue. Besides regular "full length" adventures, there were also short, encounter-size modules called "SideTreks" every so often that DMs could quickly and easily throw into any campaign on a whim or when they couldn't think of anything else to do. Later on in the WotC days, context-free maps ("Maps of Mystery") and powerful NPCs ("Critical Threats") were also added as regular features.
From 1986 to 2003, Dungeon was published every other month. Like with Dragon Magazine, Wizards eventually handed it over to Paizo for a few years, but stopped publishing it after they demanded the magazines back in 2007. Up until the Paizo days, the cover art was usually pretty decent, and was always directly related to one of the modules published in the issue. Even after Paizo took over, though, the art was still more good than bad. This decision would bite them in the ass as it lead directly to the creation of Pathfinder, eating a large chunk of Wizard's market.