Hexblade

[VonRichthofen]

Ask your DM to allow for "Extra Spell" feats not from your list.

I've seen a hexblade 12/Abjurant Champion 5 (thus, CL 17) with Shield (+9 AC) and Shivering Touch (3d6 Dex damage, no save.)
Minor Shapechange (CA) for 17 temporary hp/round, Mirror Image & Battlecaster feat with mithral full plate made for a credible defense.

It wasn't exactly over the top, but it could pull some nasty tricks - if you can handle a dragon's SR, Shivering Touch will basically paralyze it on an average roll.

But mind me, that depends on how your DM reads the feat Extra Spell.

 

[Mycanid]

It might also be interesting to give the hexblade one level of cleric in order to get Divine Might and such like.

High charisma would make it useful

I made an npc who was a CN half-elf cleric/hexblade named Zakharek who worshipped Telchur fanatically ... he was one tough opponent. But especially so if he was able to prepare himself against his foes. Seems that is when the Hexblade (not to mention the cleric) is most effective.