Quote Originally Posted by Pharaoh's Fist View Post
Half Elf Bard with a MW tool kit, Circlet of Pusuasion, 5 ranks in Bluff, Sense Motive and Knowledge: Nobility and Royalty, and max ranks in Dimplomacy should get you a decent check.

Alternatively, a cleric who casts Divine Insight and Guidance of the Avatar.
Just noting that Pharoah has summed it up very well here. the bard is mostly good because its substitution level in Races of Destiny allows you to use Diplomacy as a Calm Emotions effect, trading away the god-awful Countersong and giving you something to do in combat with your pretty self.

A 2nd level bard with a base 16 Cha and those bonuses above would have +19 to Diplomacy, I believe.