IMHO the "best" blunt weapon is the Flail of the Ages.
It is available at the DeArnisse keep and therefore fairly early in the game.Crom Fayer is good but you get it too late in the game and I'd rather keep the girdle of frost giant str and the gauntlets of ogre power
If by sword you mean longsword then blackrazor is your weapon BUT you will get to use it only in the final battle.
If you mean any edged weapon I'd say you go for the Celestial Fury.
You can get it at the Temple District of Athkatla in the guarded compound.Be prepared for a fairly tough fight but beleive me the Celestial Fury is worth it!