After the core, what is the "must have" 3.5 book?

[Flexor the Mighty!]

Not just WOTC either, and Dm orientated since I'm not doing all the splats right off the bat at least. Advice books are probably less vital than books with must have mechanics or monsters.

 

[countgray]

Fiend Folio

 

[Turanil]

Acording to my limited knowledge for that matter:

-- Unearthed Arcana
-- Expanded Psionic Handbook
-- PHB II

 

[Shemeska]

Manual of the Planes [Assuming you're intending to use the planes in your games].

Fiendish Codex I [see above]

 

[delericho]

PHB2.

Possibly XPH, if you like psionics.

The closest I can get to a DM-focusses "must have" is Unearthed Arcana, which is very useful. Otherwise, there's nothing on my shelf that I would consider truly necessary, and there's nothing that I don't have that I really think I'm missing. There are many books that are useful, and more that are good in general, but not really any "must haves".

 

[Flexor the Mighty!]

I'll probably buy FCI &II regardless since I love books on fiends, even if I dislike the Demon Lord's compared to thier excellent Dragon mag versions.

What about Green Ronin's Book of Fiends? I loved the 3.0 versions that I have since sold. How are the updates and how are the Daemons in that tome?

 

[carmachu]

whatever you like. There isnt a MUST book, its to taste.

PB II I'd say., Or Unearth Arcana.

 

[Crothian]

Spell Compendium. Not a must have, but it gets a lot of use around our table. Other then the PHB I think it is the only book all six of us own.

 

[delericho]

What about Green Ronin's Book of Fiends? I loved the 3.0 versions that I have since sold. How are the updates and how are the Daemons in that tome?

I really like that book, and also Green Ronin's "Advanced Bestiary". The Daemons are done in similar depth to the Demons and Devils, so if you liked the previous books you'll probably like them. They are themed along the lines of the seven deadly sins.

 

[Sunderstone]

Another vote for the PHBII.
If you like Psionics then another for the XPH as well.

Id also recommend the environmental books, Frostburn and Stormwrack. Sandstorm is great too but probably less useful for most due to being limited to a desert mostly.