My Dungeoneer's Bookshelf
Here is my annotated dungeoneer's bookshelf. I have not included items that are otherwise useful to classic fantasy RPG dungeon-based adventuring: GM/DM/CK/Ref guides, monster collections, campaign setting materials, and adventure modules. I have also not included those items only available as PDFs. The items below are listed in publication order, with the oldest being listed first.
Dungeoneer's Survival Guide (Advanced Dungeons & Dragons) by Doug Niles (1986): The Dungeoneer's Survivival Guide and its companion volume, the Wilderness Survival Guide, are considered by many to be classics. DSG has a section for players and a section for DMs, each a little over 60 pages. As a GM/DM/CK/Ref, I have found the player section to be more helpful in terms of providing in-game guidance to things like rope use, mining, moving in water, and variations in underground combat. There is a lot of good stuff in this section. I think that the DM section is marred by the presence of a sample underground world, "The Lands of Deepearth." It takes up a significant amount of space and I don't find it particularly helpful.
Dungeon Builder's Guidebook (Advanced Dungeons & Dragons) by Bruce Cordell (1998): Not a bad buy as a used book for a couple of bucks, but this 2E book pales in comparison to its sister volume, the ever useful World Builder's Guide. It is primarily a guide for constructing dungeons, with the ability to generate random features at each point along the way. There is a diversity of dungeon types, including underwater dungeons, aerial dungeons, and interdimensional dungeons. It's not horrible, but it lacks substance and seems a bit fluffy to me.
Dungeons by Alderac Entertainment Group (2002): A 3E supplement. Not much here, except for a few mildly interesting puzzle ideas. This is only for "dungeoneer completists." The stereotypical 3E mix of prestige classes, feats, spells, monsters and vague DM ideas, all gathered around the dungeon theme.
Dungeoncraft (Legends & Lairs, d20) (2003): Part of the highly-esteemed "Legends & Lairs" 3E supplements from Fantasy Flight Games. This book contains the usual 3E mix of prestige classes, feats, spells and monsters. However, the second half of the book--covering dungeon crafting--is a gold mine for the GM/DM/CK/Ref building and running a dungeon adventure/campaign. The two companion volumes--Traps & Treachery I & II--are also pretty good.
Dungeonscape: An Essential Guide to Dungeon Adventuring (Dungeons & Dragons d20) (2007): I would say that this book is not too bad, were it not for the fact that the best content is also found in the D&D 3.5E DMG. I have found the companion volume, Cityscape, to be more useful. A decent collection of traps give this book some value.
Engineering Dungeons by Robert Doyel (2008): A very business-like accessory for Castles & Crusades. This is useful for just about any RPG using underground space. The heart of this book is a no-frills random dungeon generator. There is less variety here than in the Dungeon Builder's Guidebook, but there is more attention to detail. It is the detail and the text that makes this book valuable even if you are not generating a random dungeon.
As I get into our current Castles & Crusades homebrew campaign, Isles of Emmon, I find myself paging through these books for ideas. My own dungeoneer's canon starts with two books: AD&D DMG (Gygax) and the AD&D 2E Campaign Sourcebook and Catacomb Guide/Dungeon Master's Guide/Rules Supplement (Jaquays). To these I would add two books from my dungeoneer's bookshelf: AD&D Dungeoneer's Survival Guide (Niles) & Dungeoncraft (Legends & Lairs, D20). Finally, when I need help with the nuts and bolts, I use Engineering Dungeons as my go-to dungeon generator.
Anything missing from this list? Is there anything that you have found helpful?