Halp.

[blind sight]

Looking for a template with an LA +4 or less that gives as high of a CHA as a bonus as possible.

[Ithamar]

Use the variant half-fiend template to be a half-succubus.

Be a necropolitan and get evolved x 4 for +8 CHA.

Saint template is +2 LA and gives a ton of useful stuff and +4 CHA.

What is the build you're looking for?  What is the current base creature?

[ariasderros]

Half-Giant (+1LA) can take Primordial (+0LA) for +4 Cha
Unseely (+0LA) for +2 Cha
Magic-Blooded  (+0LA) for +2 Cha
Half-Fey (+2LA) for +4 Cha
Pherenic (+2LA) for +4 Cha

So if you're not able to take Half-Giant, or don't want to, you can combine Half-Fey and Pherenic for +8 Cha for +4LA (which seems to be par) and add in the other two for another +4 Cha, totaling +12 and a lot of other benefits.

[Jackinthegreen]

Half-Giant (+1LA) can take Primordial (+0LA) for +4 Cha
Unseely (+0LA) for +2 Cha
Magic-Blooded  (+0LA) for +2 Cha
Half-Fey (+2LA) for +4 Cha
Pherenic (+2LA) for +4 Cha

So if you're not able to take Half-Giant, or don't want to, you can combine Half-Fey and Pherenic for +8 Cha for +4LA (which seems to be par) and add in the other two for another +4 Cha, totaling +12 and a lot of other benefits.

Phrenic requires the character not already have the psionic subtype.

Of course, it makes little difference since a Primordial Draconic Unseely Magic-Blooded Half-Fey Half-Giant would be +4 and get +14 charisma.

[littha]

Half celestial is also +4 Cha though that is a +4 LA

[Dawnmor]

This isnt a Template, but why not go Pixie?, They get a +6 cha, easy.

Or better yet, go Pixie, grab Rogue/Sorcerer, Grab sorcerer enough to get up to atleast 3 or 4th level spells, then take Arcane trickster and Spellwarp sniper.

The funny thing is that Sneak attack applies to ray spells and also applies to Range touch spells, Sneak attack with melfs acid arrow . or an orb of force for added amusement.

[littha]

I can not emphasise enough to not play a spellcaster with +4 LA...

[Ithamar]

It's for a gestalt game, and LA only takes up one side.

[SorO_Lost]

Lesser Half-Giant (+0LA) can take Primordial (+0LA) for +4 Cha
Unseely (+0LA) for +2 Cha
Magic-Blooded  (+0LA) for +2 Cha
Half-Fey (+2LA) for +4 Cha
Pherenic (+2LA) for +4 Cha
= +16 Cha for +4 LA.

Mitigate Persist, get one heck of a Runestaff or dip around and...

Charisma Boost - Spells
Greater Visage of the Deity (SPC): 9th, good/evil +4/+2 unnamed. If cast from an item you can UMD being Good Aligned.
Snowsong (FB): 6th level and unpersistable, but provides a +4 moral boost to you an the entire party.
Nixe's Grace (SpC): 6th level, +8 enhancement bonus and some other stuff. +2 better than an item.
Righteous Aura (SpC): 4th and paladin only, +4 sacred. At 1/hour per caster level, UMDing a wand of it works just fine.
Devil's Ego (FCII): 3rd level, +4 profane and your type changes to outside, can be used on Undead to set up Polymorph.

Charisma Boost - Items
Spellcaster Services[Wish] (Core): Paying for five spells comes out to 132,650 which is 5k cheaper than a Tome.
Luhix (BoED): a plant based drug (use minor creation) for a +2 alchemical bonus, get a a ring of mind over body too.
Hoseshoes of Flame (SS): +6 unnamed, uses boot & arms and requires UMD.
Command (DotF): +4 competence. Note "command" has been reprinted a half dozen times but this is the only +2 version. Your DM may not allow it.

Charisma Boost - Misc
Worm of Minauros (FCII): magical location, +1 unnamed to highest ability score for 30 days for 8k.
Faustian Pact (FCI): +1 unnamed to any and you'll want the insidious version (page 24) to pick up an extra feat as well.
Age (Core): +3 to all mental scores and -6 to physical scores. Use polymorph to fix physical scores.
Level Bonus (Core): hey can't forget this, up to +5 by level twenty.

Charisma: 83 (+36) = 18 (base) + 4 (racial:prime) + 2 (racail:unseely) + 2 (racail:magic) + 2 (racail:fey) + 4 (racail:pherenic) + 3 (age) + 5 (level) + 5 (inherent) + 1 (pact insidious) + 1 (worm) + 4 (competence) + 6 (horseshoes) + 8 (enhancement) + 4 (moral) + 4 (sacred) + 4 (profane) + 4 (visage of the deity) + 2 (alchemical)

To put things into prospective, you get eight to nine bonus 9th level spells per day and your bonus to Save DCs is higher than the total sum of your average optimized character (34 stat & 9th lvl spell = DC 31). Add Snowcast, Draconic Aura, Draconic Power, Cold Focus, Greater Cold Focus, Icemail Armor, for an additional +9 to all Save DCs if you feel the need and your Cantrips have a Save DC of 58. Even a Terrasqua needs a natural 20 on his Fort Saves, and he has 48HD

[Dawnmor]

Yeah Pixie is a +4 LA, but! you get a +8 Dex, +6 Cha and for me that SCORES!, natural invisiblity too which also helps.  Saint for +4, Half Celestrial for +4, if you want to add on Power that is.  Grab 2 levels of Paladin or any PRC that gives Cha mod to Saves and your set.

[littha]

Yeah Pixie is a +4 LA, but! you get a +8 Dex, +6 Cha and for me that SCORES!, natural invisiblity too which also helps.  Saint for +4, Half Celestrial for +4, if you want to add on Power that is.  Grab 2 levels of Paladin or any PRC that gives Cha mod to Saves and your set.

This is all true but for a spellcaster in a non-gestalt game you are 2 spell levels behind where you should be

[Dawnmor]

yes however, if you read it correctly, he said this is a Gesalt game, All templates on one side and class levels on the other.

[Jackinthegreen]

Lesser Half-Giant (+0LA) can take Primordial (+0LA) for +4 Cha
Unseely (+0LA) for +2 Cha
Magic-Blooded  (+0LA) for +2 Cha
Half-Fey (+2LA) for +4 Cha
Pherenic (+2LA) for +4 Cha
= +16 Cha for +4 LA.

Mitigate Persist, get one heck of a Runestaff or dip around and...

Charisma Boost - Spells
Greater Visage of the Deity (SPC): 9th, good/evil +4/+2 unnamed. If cast from an item you can UMD being Good Aligned.
Snowsong (FB): 6th level and unpersistable, but provides a +4 moral boost to you an the entire party.
Nixe's Grace (SpC): 6th level, +8 enhancement bonus and some other stuff. +2 better than an item.
Righteous Aura (SpC): 4th and paladin only, +4 sacred. At 1/hour per caster level, UMDing a wand of it works just fine.
Devil's Ego (FCII): 3rd level, +4 profane and your type changes to outside, can be used on Undead to set up Polymorph.

Charisma Boost - Items
Spellcaster Services[Wish] (Core): Paying for five spells comes out to 132,650 which is 5k cheaper than a Tome.
Luhix (BoED): a plant based drug (use minor creation) for a +2 alchemical bonus, get a a ring of mind over body too.
Hoseshoes of Flame (SS): +6 unnamed, uses boot & arms and requires UMD.
Command (DotF): +4 competence. Note "command" has been reprinted a half dozen times but this is the only +2 version. Your DM may not allow it.

Charisma Boost - Misc
Worm of Minauros (FCII): magical location, +1 unnamed to highest ability score for 30 days for 8k.
Faustian Pact (FCI): +1 unnamed to any and you'll want the insidious version (page 24) to pick up an extra feat as well.
Age (Core): +3 to all mental scores and -6 to physical scores. Use polymorph to fix physical scores.
Level Bonus (Core): hey can't forget this, up to +5 by level twenty.

Charisma: 83 (+36) = 18 (base) + 4 (racial:prime) + 2 (racail:unseely) + 2 (racail:magic) + 2 (racail:fey) + 4 (racail:pherenic) + 3 (age) + 5 (level) + 5 (inherent) + 1 (pact insidious) + 1 (worm) + 4 (competence) + 6 (horseshoes) + 8 (enhancement) + 4 (moral) + 4 (sacred) + 4 (profane) + 4 (visage of the deity) + 2 (alchemical)

To put things into prospective, you get eight to nine bonus 9th level spells per day and your bonus to Save DCs is higher than the total sum of your average optimized character (34 stat & 9th lvl spell = DC 31). Add Snowcast, Draconic Aura, Draconic Power, Cold Focus, Greater Cold Focus, Icemail Armor, for an additional +9 to all Save DCs if you feel the need and your Cantrips have a Save DC of 58. Even a Terrasqua needs a natural 20 on his Fort Saves, and he has 48HD

IF the BoEF is allowed, there's also a spell called Beauty's Caress that grants a 5d4 enhancement bonus to Charisma. Bard 3, Imagist 3, Cleric 4.  It's a pretty big if, but something to consider for min-maxing purposes.

[littha]

yes however, if you read it correctly, he said this is a Gesalt game, All templates on one side and class levels on the other.

You were suggesting pixie before he said anything about gestalt.

[SorO_Lost]

IF the BoEF is allowed, there's also a spell called Beauty's Caress that grants a 5d4 enhancement bonus to Charisma. Bard 3, Imagist 3, Cleric 4.  It's a pretty big if, but something to consider for min-maxing purposes.

Holy mother of Pelor 

*ding*, did someone order 100 Charisma? Would you like fries with that? You can have a bag of potato chips and eat it too.

[Halinn]

IF the BoEF is allowed, there's also a spell called Beauty's Caress that grants a 5d4 enhancement bonus to Charisma. Bard 3, Imagist 3, Cleric 4.  It's a pretty big if, but something to consider for min-maxing purposes.

Holy mother of Pelor 

*ding*, did someone order 100 Charisma? Would you like fries with that? You can have a bag of potato chips and eat it too.

The only problem is that it's 3rd party...

[SorO_Lost]

Eeewwww....

*beat*

Wait that's the porn book isn't it?

[Jackinthegreen]

IF the BoEF is allowed, there's also a spell called Beauty's Caress that grants a 5d4 enhancement bonus to Charisma. Bard 3, Imagist 3, Cleric 4.  It's a pretty big if, but something to consider for min-maxing purposes.

Holy mother of Pelor 

*ding*, did someone order 100 Charisma? Would you like fries with that? You can have a bag of potato chips and eat it too.

The only problem is that it's 3rd party...

The only problem?  Most DMs would say it's too overpowered to have.  At just one spell level higher than Eagle's Splendor it's an average of 12.5 charisma (and appearance, if using those rules) before metamagic and a base 1hr/level duration.  Cast it on a Charisma-based anything and it's going to town.

Eeewwww....

*beat*

Wait that's the porn book isn't it?

Yes, it's the porn book.  I'd suggest you stop beating off to it. 

[Libertad]

The only problem?  Most DMs would say it's too overpowered to have.  At just one spell level higher than Eagle's Splendor it's an average of 12.5 charisma (and appearance, if using those rules) before metamagic and a base 1hr/level duration.  Cast it on a Charisma-based anything and it's going to town.

Even crazier is that there's a Prestige Class in there called Metaphysical Spellshaper which allows you to take ability damage in place of increasing the level of a level with metamagic feats.  At 3rd level in the PRC, all spell level increases for metamagic feats are reduced by one (non-cumulative, a silent, still fireball still uses a slot one level higher).

Take 2 Strength damage, get Maximized Beauty's Caress.  +20 Charisma/Appearance.

[SorO_Lost]

Yes, it's the porn book.  I'd suggest you stop beating off to it. 

That would explain why yours is so sticky >.<