Li Shenron
Legend
I thought about it and here are my three suggestions (I own these myself and I've loved them):
Manual of the Planes : it's the core 3.0 reference for planar rules and works probably fine with 3.5 as well, although you have some of these rules in the 3.5 DMG; it's a great source of ideas and a guide to develop your own ideas instead; finally it's the book I enjoyed most to just read in bed
Oriental Adventures : you will not get 3.5 oriental materials in one single book anymore, since the stuff has now been split up into the Complete books and maybe somewhere else (which is something I personally dislike at the extreme), but also if you don't get those 3.5 books, you can still use 99% of OA in 3.5; in any case it's one of the best books written in 3ed, with a large number of ideas which all stay together neatly
Faith & Pantheons : yes this is a FR book which may turn you away from it; however it has been for us an immense source of inspiration for characters and adventures alike; we have decided to adopt the FR pantheon even without playing FR because it is very well designed, but you can also just pick a patron deity for a character and use the information here as a guide to roleplay a PC focused on one ethos; the only part of this book which you won't ever need is the deities' stats (only major deities have them, but it's not a huge part of the book)
I wouldn't suggest you to get the classbooks even if I have them all. They're nice, but most of the stuff is already reprinted with minor differences. However the are also cheap so I won't say it's a bad idea to get them.
Completely forget about the following:
Deities & Demigods - most unuseful book ever: the general rules for creating a pantheon or handling religions are questionable or otherwise you could figure them out yourself; the deities stats are here more important than description, in case you need a deity stat, it's much more reliable to just make a high-level or even epic NPC and give it extra custom powers; the book is split into 4 pantheons, each of which is incomplete, and you probably never need more than one or two of these
Epic Level Handbook - the basic rules are the same in 3.5 DMG, and everything else is quite messy; some stuff is not truly epic and other stuff is too much epic power-wise
Hero Builder's Guidebook - it had a couple of interesting thing, probably totalling less than 5 pages, which should have been made a web enhancement
Manual of the Planes : it's the core 3.0 reference for planar rules and works probably fine with 3.5 as well, although you have some of these rules in the 3.5 DMG; it's a great source of ideas and a guide to develop your own ideas instead; finally it's the book I enjoyed most to just read in bed
Oriental Adventures : you will not get 3.5 oriental materials in one single book anymore, since the stuff has now been split up into the Complete books and maybe somewhere else (which is something I personally dislike at the extreme), but also if you don't get those 3.5 books, you can still use 99% of OA in 3.5; in any case it's one of the best books written in 3ed, with a large number of ideas which all stay together neatly
Faith & Pantheons : yes this is a FR book which may turn you away from it; however it has been for us an immense source of inspiration for characters and adventures alike; we have decided to adopt the FR pantheon even without playing FR because it is very well designed, but you can also just pick a patron deity for a character and use the information here as a guide to roleplay a PC focused on one ethos; the only part of this book which you won't ever need is the deities' stats (only major deities have them, but it's not a huge part of the book)
I wouldn't suggest you to get the classbooks even if I have them all. They're nice, but most of the stuff is already reprinted with minor differences. However the are also cheap so I won't say it's a bad idea to get them.
Completely forget about the following:
Deities & Demigods - most unuseful book ever: the general rules for creating a pantheon or handling religions are questionable or otherwise you could figure them out yourself; the deities stats are here more important than description, in case you need a deity stat, it's much more reliable to just make a high-level or even epic NPC and give it extra custom powers; the book is split into 4 pantheons, each of which is incomplete, and you probably never need more than one or two of these
Epic Level Handbook - the basic rules are the same in 3.5 DMG, and everything else is quite messy; some stuff is not truly epic and other stuff is too much epic power-wise
Hero Builder's Guidebook - it had a couple of interesting thing, probably totalling less than 5 pages, which should have been made a web enhancement
