Persist Time Stop (3.5e Optimized Character Build)
From D&D Wiki
Time stop is a domain spell of the Planning domain, and by using divine metamagic persist spell you can make time stop last for 24 hours! (Effectively Time Stop has no duration and is an instantaneous effect. Therefore Time Stop can't be persisted. You can't exploit this unless your DM doesn't know it.)
PHB, Complete Divine, Spell Compendium
 Game Rule Components
Time Stop, Time/Planning Domain
Starting Ability Scores (Before Racial Adjustments): As high as Cha and Wis as possible, get Cha to at least 18, and Wis to at least 19
Race (Templates): Any
Starting Racial Traits: Any
|Saving Throws||Feats|| Class
|1st||Cleric 1||+0||+2||+0||+2||Extra Turning, Extend Spell||Turn Undead||Planning Domain|
|3rd||Cleric 3||+2||+3||+1||+3||Persistent Spell|
|6th||Cleric 6||+4||+5||+2||+5||Divine Metamagic (Persistent Spell)|
You continue taking the levels in cleric until you can cast time stop.
Time Stop has a range of personal and a non-instantaneous duration (1d4+1 rounds) so persist can be added onto it to make it able to last 24 hours long! Imagine the possibilities, cast the spell, then spend 24 hours to dig a giant hole to bury the enemies in. Plus if you only spend 14-15 hours doing stuff, you can grab 8 hours of sleep and prepares your spells and cast it again before the first one ends!
 Munchkin-Size Me
Go ahead and take Divine Metamagic (Extend Spell) in order to double the amount of buffs you can keep persistent on yourself as well. You'd only have to cast a 48 hour buff every other day.
Seriously you can't take it much further than this. Maybe add "spontaneous cast domain spell" from PHB2
Of course a DM could rule you age 100 years per day of persistance. Since time flows normally for you, but slowly for everyone else.
Optionally, using the Player's Guide to Faerun, you could make a Wiz14/Incantrix3, then try to really pump the Spellcraft skill. Cast Time Stop normally, then within, make a DC63 Spellcraft check to make it Persistent.
 Side Notes
None for now.
I can't think of any. Besides DMs who may not let you use persist even though it's an offical feat.
A secondary issue with this build, is that time stop is a level 9 spell, and the feat Persistent spell uses a slot 6 slots higher than the base spell. In this instance, you would have to have access to a level 15 spell slot to take advantage of this build.
That is what divine metamagic is there for. You give up 7 turning attempts in place of the 6 spell slots.
 DM Counters
There is an epic feat that if you take it, allows you to act as if a spell with the range of personal that an enemy cast also affected you.
It is way too OP, but I propose this instead:
Start as Wizard, get Extend Spell, which makes your spells last twice as long. Get 10nth level spell slot as soon as posible (I think you need epic level for this, and definietely > 17). You'll also need 20+ int. Use that 10nth level slot to store extended time stop (works better than empowered!) Get a level of Archmage and trade a 5th level spell slot and 10nth level spell slot to be able to cast Extended Time Stop twice per day as a spell-like ability.
Ability to cast 4-10 turn Time Stop twice a day is quite powerfull, but you need to be epic level and have to sacrifice 1 feat and 1 Archmage level for this. I'm not counting extend spell because it is quite usefull for buffs.
You can do that multiple times, up to 4 for Wizard and up to 5 for Sorcerer (5 is maximum level for Archmage), each time sacrificing a feat for another 10nth level spell slot and one level of Archmage.
To munchkin-size you can add more spell slots (11th, 12th, 13th, and so on) and more metamagic feats prior to taking a level in Archmage, but that would reqire insanely high level. Extend, Empower, Maximize, Qiucken and Intensify Spell could be used here. Extended Intesified Time Stop is lvl 18, but lasts 15 (or 20 depending on GM) turns! If you are willing to go this far, you might as well sacrifice an epic feat and 18th level spell slot for extended time stop at will as a spell-like ability.
To make it even more OP negotiate with Yor GM the possibility of researching "Timelessness" spell (whenever someone in your proximity casts Time Stop it works for you as well) and creating magic items with constant "Timelessness" for everyone in your party. At the very least every spellcaster in your party of Epic level should take Spell Stowaway [Epic, Time Stop].
You can also "downsize", and get a lavel of Archmage at 17nth level while learning Time Stop for the first time.
To squeze even more out of your Time Stops use haste (Extended haste is very usefull in its own right). It gives one partial action per turn. Most people use it for an extra attack at maximum BAB, but for a wizard it is more usefull to combine 2 partial actions into one action and cast extra spell at the beginning of your next round. That extra spell can be easilly disrupted if you take damage, but not under Time Stop :) You get 3 spells per 2 rounds, so 6 in 4 rounds, 9 in 6, 12 in 8 and so on. Oh, and don't forget to use Quicken Spell. It requres a spell slot 4 levels higher, but is still good for low level buffs, magic missle and the like. IMO combining haste, time stop and quicken spell is pushing it, but if your GM allows it, and you manage to cast time stop that lasts 4 rounds while hastened, you can cast 6 high level spells and 4 qickened spells. If your GM says haste does not work under Time Stop, use it to cast 3 Time Stops in 2 normal rounds instead.
You could also get an item with Time Stop once a day, or even a few of them.
A staff with Time Stop that costs 10 charges should also be affordable. To Munchkin-size get a feat that allows you to use metamagic by burning extra charges and either get a staff with time stop that costs 9 charges for extra extend spell, or one with around 40 charges per time stop to get maximize extend empower and maybe quicken almoust for free. Use efficient quiver to store them and be prepared to quickly burn through hundreds of thousands of gold worth of staves.