StarDestroyer.Net BBS

We're not talking the core books, obviously, DMG, MM, or PHB, but any of the hundreds of outher books which have been produced,

Me, I love Book of Exalted Deeds. All sorts of kewl feats for fighting evil and making your pc feel like a good pc, as opposed to just having a good alignment. Ive had too many pcs, andseen too many, that were just nominally good.

So, whats yours?

The Black Company D20 and Arcana Unearthed.

The Book of Vile Darkness... some of the spells in there are just bastardousous and cruel.

Plus it has decent rules for drugs to flesh things out.

Wotc: Tie between Book of Vile Darkness and Draconomicron

Series (Tie): Malhavoc Press; The * Might Series
Mongoose Publishing: Encycloedpia Arcane/Divine/Psionica Series

Non-Series, No Wotc: Elementalism (Mongoose Publishing, Encyclopedia Arcana)

SW Ultimate Alien Anthology. It's got 180 species, particularly Episode I & II aliens, detailed with background info, culture, abilities & stats, height & age range, and example names.

I use it exclusively for converting to D6.

I'll echo Exalted Deeds. Shiny celestial pwnage in hardcover form.

Stargate. Nicely done.

WotC: Draconomicon
Non-WotC: Traveller20

Edited because ZOMG I'M AN IDIOT. D20 Sourcebooks.

The Book of Exalted Deeds. The feats are kick-ass and it has a lot of interesting prestige classes (the Risen Martyr is my favorite). The artwork is pretty good, too.

Does the Planescape campaign setting count? If not, then the Forgotten Realms setting is an awfully nice book.

Forgotten Realms.

The Black Company Campaign Setting
and
The Wurst Of Grimmtooth's Traps (guess why)

Mecha Compendium. Mostly because it's the only D20 product by DP9 so far, but also because they actually made mecha tough. The average stormtrooper shot will do 3.5 damage to a scout Gear, and no damage to anything heavier. General Purpose mecha have DR 15, and Striders have 22-25, as opposed to the AT-AT's crappy-for-its-size 15.

Draconomicon. Hands down, no contest. For game use I would say the Forgotten Realms Campaign Setting, but the Draconomicon is one that I can (and do) just sit down and read, even when I'm not readying a dragon to throw at an unfortunate adventuring party.

Complete Mafia for D20. Fell in love with it at playtest at cons, and remain basically unimpressed by the rest of the D20 I've seen.