I can't find...

[Azoth]

Any base classes or PRCs designed to hunt or kill demons/devils. I have found several for the eradication of dragons and other monsters, but no such luck for outsiders. Are there any feats/classes/PRCs designed to hunt or kill demons, devils, or even celestials?

I am not looking for homebrew, but actual WoTC printed sources.

[kardar233]

The Hellreaver (FCII) is specifically for killing fiends.

[DarkestKnight]

Knight of the chalice, and hellreaver both do. Knight of the chalice focuses on demon/devils, and hellreaver takes on anything evil, though fluffwise it is focused against devils. I have nothing for hunting celestials though.

EDIT: Curse you swordsages!

[gorfnab]

Sacred Exorcist (CD)
Exorcist of the Silver Flame (ECS)

[Keld Denar]

Hellbreaker and the cleric one from the same book as Hellreaver. Hellbreaker gets a lot of features of Spellthief as far as breaking down SR and the resistances of outsiders.

Heck, by that regard, Spellthieves don't do bad. They can steal SLAs and SUs from outsiders (who generally have plenty of them), as well as soften them up for other heavy hitters.

[Biffoniacus_Furiou]

Sacred Exoricst (CD), or just about any prestige class from FCII.

There are tons of spells which specifically combat evil outsiders, so just a primary Wizard or Cleric would be more than sufficient.

[Venger]

Any base classes or PRCs designed to hunt or kill demons/devils. I have found several for the eradication of dragons and other monsters, but no such luck for outsiders. Are there any feats/classes/PRCs designed to hunt or kill demons, devils, or even celestials?

I am not looking for homebrew, but actual WoTC printed sources.

demonwrecker from expedition to the demonweb pits is a pretty great class.

foe hunter can work too, if you're low-op.

[Psyren]

Exalted Arcanist (BoED) is designed to roast all evil creatures rather than fiends specifically, but they are quite suited to it all the same. They're especially handy for dropping large AoE on the party and only hurting the enemy.

[Darius Kane]

Paladin or Ranger.