If you were stranded on an island w/ 3 books...

[Lord Mhoram]

Expended Psionic Handbook
Magic of Incarnum
Ultimate Feats (from Mongoose)

If I'm on a desert island, I'll have plenty of time to come up with adventures and adversaries (whether monsters or characters), and I always use my own settings, so I take the books that have the rules I want.

 

[Wystan]

Spycraft 2.0
Arcana Evolved
Villains and Vigilantes (or mutants and masterminds to stick with D20)

Now I have Fantasy, Spy, Alternate Fantasy, and Supers.

I am set....and I can easily do set ups for desert or island adventures...

 

[freebfrost]

1. Conan RPG
2. Spell Compendium
3. DMG II

 

[MadMaxim]

Eberron Campaign Setting, Forgotten Realms Campaign Setting and Draconomicon.

 

[Queen_Dopplepopolis]

Mutants and Masterminds 2nd Edition

Hmmm, this is a good choice, Fru. You can do anything with Mutants and Masterminds... *ponders*... I may have to change my selections.

 

[drothgery]

Are we assuming that despite being stranded on said island, there's a fully equipped and staffed luxury resort my gaming group is staying at free of charge, because otherwise we'd be preoccupied with getting off the island, not gaming, even if we're in no danger of starving ...

Eberron Campaign Setting - for D&D
Mutants & Masterminds 2.0*- for anything else
A really good mega-adventure of my DM's choice - because even on a desert island with nothing else to do, coming up with something new for every game is hard

* I don't actually have this, due to Green Ronin's distributor having trouble getting stuff to Amazon.com, but I like the ideas and previews, and I've got a copy on order.

 

[Ralif Redhammer]

Hmmm. Tough call to make.

Assuming that the core 3.5 books are instead replaced with the core C&C books:

Manual of the Planes
Castle Zagyg: Yggsburgh
Tome of Horror I

 

[BiggusGeekus]

Ptolus
Ptolus
Ptolus

... then I'd bind the three copies together out of jungle vines and have a raft!

 

[Glyfair]

Are we assuming that despite being stranded on said island, there's a fully equipped and staffed luxury resort my gaming group is staying at free of charge, because otherwise we'd be preoccupied with getting off the island, not gaming, even if we're in no danger of starving .

Don't forget trying to win the million dollars.

Oops, wrong island

 

[Remathilis]

Eberron Campaign Setting
Monster Manual III
Spell Compendium