The Tomes

[Surgo]

It seems like there's a decent number of "let's remake 3.5" projects going around, which is cool. Nobody seems to remember the original 3.5-remake-that-actually-got-somewhere project though, which is a shame because this day it remains some of the highest-quality material you'll find anywhere. They also contain some of the best fluff you'll find anywhere (which makes them rather pleasant to read), with an especially excellent treatment for DMs on campaigning on the planes

They're also meant to be easily pluggable into any game -- you can use one book or all the books, or only some of the material in one or more of the books.

So, in order of publication, the tomes are:
Tome of Necromancy -- a reimagining of the rules of necromancy. Discusses at length how to fit necromancy into your game, presents many new necromancer prestige classes that you might actually want to take if you're a necromancer, contains an overhaul of how undead work through use of two subtypes, and contains some feats and other abilities that make undead more interesting opponents. Also gives low-level necromancers (the wizard specialists) some more interesting spells to use, something Necromancy lacks at those levels.

Tome of Fiends -- my personal favorite and not so much an overhaul as a supplement. Provides lots of great information and inspiration for running a campaign on the lower planes, and also contains new rules for generating level-appropriate fiend opponents (and PCs) through use of new base classes and feats. As the book says: "While many people are able to parrot a vague game mechanical definition of what a fiend is (an extraplanar creature with an origin in the lower planes or an extraplanar creature with the [Evil] subtype), almost noone can agree on what exactly it is that a fiend does. And therein lies the heart of the problem, and the reason this series has taken upon itself to address this nest of serpents."

Dungeonomicon -- dungeons. We all use them, but do we really take the time to think about why they exist? This book does. It also stops to think about the impact other aspects of D&D would have on the world -- like certain spells (such as Wish and Planar Binding). It also talks about living underground.

Races of War -- basically, making your fighting men equal to your wizards. Probably the most radical of all the books.

Book of Gears -- the last Tome, and also unfinished. It contains a new way to handle wealth and advancement, something sorely needed in D&D 3.5.

I didn't write them or anything, I just use them in my games and I think they're great. The fluff especially, I really can't say anything that will do it justice. So yeah, I hope if you haven't seen these before you can read and enjoy them, and consider their use in your game.

[Tavar]

Just one thing to note: the Tomes use the tier 1 classes as a balance point, so the classes contained within can be exceptionally powerful. Still, the do manage the balance well at that level, so it might not be a bad thing.

[Nero24200]

They also contain some of the best fluff you'll find anywhere (which makes them rather pleasant to read)

This, to me, is the main reason why I don't bother with the Tomes. I prefer to read a set of rules which don't make me feel like I'm being talked down to. It becomes hard to see the material as written to a proffessional standard when the description for a feat is "I'm Speedy McSpeedyson". You can say the fluff is nice and say the material is good, but saying it's pleasent to read just plain isn't true for alot of people.

[Mongoose87]

This, to me, is the main reason why I don't bother with the Tomes. I prefer to read a set of rules which don't make me feel like I'm being talked down to. It becomes hard to see the material as written to a proffessional standard when the description for a feat is "I'm Speedy McSpeedyson". You can say the fluff is nice and say the material is good, but saying it's pleasent to read just plain isn't true for alot of people.

I actually found the tone of most of the Tome material I've read rather amusing.