I like Tome of Battle mixes or Gish Mixes, since I've played a couple and found them to give more substantial low level playing power. These builds get progressively shadier --- eventually ending in retraining a first level feat to precocious apprentice if you're DM lets you get away with that.
Flaw feat: Militia (FRCS) - All martial Weapons (Abjurant Champion, Spellsword)
Flaw feat: Combat Casting (Abjurant Champion)
Level 1 Feat: Spell Focus: Evil (ur-Priest)
Level 3 Feat: Iron will (Ur-Priest)
Level 6 Feat: Shape Soulmeld - Ring of Evasion or LA buyoff frees up these feats
Level 9 Feat: Open Least Chakra.
Savage Bard 1, Wizard 3, X1, Ur Priest 1, Spellsword 1, Abjurant Champion 3, Sublime Chord 1, Fochlucan Lyracist 9.
Bard 1, Battle Sorcerer 3, Cleric 1 (Fort/Will), Urpriest 1 (Fort/Will), Spellsword 1 (Fort/Will), Abjurant Champion 3, Sublime Chord 1, Fochlucan 9
This uses the kobold trick for the extra sorcerer caster level to qualify for Spellsword, but requires more feat strangeness; you're going to need to use item locations for Iron will.
Bard 1, Wizard 3, Cleric 1, Ur Priest 1, Crusader 1, Jade Phoenix Mage 3, Sublime Chord 1, Fochlucan Lyracist 9.
Bard 1, Battle Sorcerer 3, Cleric 1, Ur Priest 1, Crusader 1, Jade Phoenix Mage 3, Sublime Chord 1, Fochlucan Lyracist 9.
Uses Kobold trick or White Dragonspawn with LA buyoff to Qualify for Jade Pheonix Mage. -- again, feat issues.
Crusader 1, Bard 1, Battle Sorcerer 3, Ur Priest 1, Jade Pheonix Mage 4, Sublime Chord 1, Fochlucan Lyracist 9.
Ur-Priest Qualification with no cleric dip.
To increase the crazy a little more: You use Precocious apprentice to qualify for Jade Pheonix Mage, then retrain a battle sorc level to a JPM level. The reason to do this is to pick up Thicket of Blades at JPM5.
Bard 1, Battle Sorcerer 1 (2), Cleric 1, Ur Priest 1, Crusader 1, Jade Pheonix Mage 5, Sublime Chord 1, Fochlucan Lyracist 9.
Using Precocious apprentice cheese, plus illumian heighten cheese to qualify for Sublime Chord, maximizing number and variety of manouvers:
Rogue 1/Bard 1/Battlesorc1/Cleric 1/Monk 1/Urpriest 1/Swordsage 2/Warblade 1/Crusader 1/Sublime Chord 1/Fochlucan Lyracist 9
You can fit in duskblade:
Savage Bard 1, Duskblade 4, Ur Priest 1, Spellsword 1, Abjurant Champion 4, Fochlucan Lyracist 9.
For: 19 BAB, 18 Duskblade casting, 10th UrPriest casting.
Or:
Savage Bard 1, Duskblade 4 Ur Priest 1, Spellsword 1, Abjurant Champion 4, Sublime Chord 1 Fochlucan Lyracist 8.
Less smooth, getting 9th SC and UP casting, 18 BAB.
Squeeze in your favourite Wizard prestige class, probably Incantatrix:
Savage Bard 1/Wizard 3/Urpriest 1/X2/Incantatrix 4/Sublime Chord 1/Fochlucan Lyracist 9
X1 has to progress wizard casting. Mindbenders perfect, as per usual. Heck, go divine orcale, free up a feat.
Beguiler ToB variant: Beguiler4/Savage Bard 1/Urpriest 1/Martial Class 1/Jade Phoenix Mage 3/Sublime Chord 1/Fochlucan Lyracist 9.
---17 BAB, 16.75 if you choose swordsage (hint, don't).
You get melee, Tome of Battle Goodies, 9th level Arcane and Divine Casting, 10th level Bardic Music, Trapfinding, Evasion, insane skills. All you need is a way to break the action economy.
Another option: Beguiler 3, and go Beguiler 3/Savage Bard 1/Martial Class 1/Urpriest 1/Mindbender 1/JPM3 --- trade Beguiler 4 for the hilarity of mindbender.
Casting options:
Warmage, Beguiler, Dread Necromancer, Sorcerer, Wizard, Battle Sorcerer; pick what you want. Or do bard like you're supposed to.
Every build here gets 17 or 18 BAB, base saves of 9+/9+/18+ (medium, medium, extra good, with lots going 12/10/20 or 13/10/22). Every build gets 9th or 10th level sublime chord casting. Every build has an average hit die of at least a d6. Every build gets 9th or 10th level bardic music. Every build gets Arcane spells from 0-3. Every build gets insane skill points, all of which are tied up under level 11. You can mix trapfinding into every build except the Battlemage/Sorc/Dread Necromancer/Beguiler/Warmage with tome of battle build. (Beguiler will get it). Full cleric casting. Full party worth of power, in a single character.
I love the Fochlucan Lyracist, actually.