This list identifies the most highly-regarded Dungeons & Dragons (D&D) adventure modules of all time based on the rankings from GeekDo, RPG.net, Dungeon Magazine, and the Hahn Library. I realize you could use solely Dungeon's list or this list of GeekDo favorites, but neither aggregates the ratings and rankings across several sources.

To facilitate the play of these modules, I've made an effort to place all of these modules into various campaigns that focus on a specific setting, theme, or storyline. The campaign with which I associate each module is noted in its description.

Method: Adventures all must be in the top 10 of GeekDo, RPG.net, Dungeon, or Hahn Library, in the top 20 of two of those lists, or the top 30 of three. They must also have at least 12 votes or ratings (counting RPG.net reviews as 4 ratings) from at least one source. I put all adventures that make that cut together into a single list of modules, ranked them based on ratings from each source, and averaged the four rankings together to get the final order below.

Update 1/26/10: I added several modules and that recently reached at least 12 ratings on GeekDo. Recent ratings also shifted the rankings of many modules that had already been on the list.
Update 1/29/10: I incorporated Dungeon's ranking, which tend to correspond with the GeekDo ranking but still promoted a couple overlooked modules that RPG.net likes.
Update 2/1/10: I added the rankings from the Hahn Library, which actually include more votes than any other ranking so far.