Damage vs Critical

[Fax Celestis]

In 3.0 a Weapon Master with a keen Scimitar, Rapier or Falchion and the improved critical feat could get 10-20. If you allow Weapon Master (or the overpowered Psychic Weapon Master) in 3.5 you can still get 13-20 since the only thing you're missing out is the keen property.

9-20, actually, and increased the multiplier too. 9-20/x7 is a thing of beauty.

The excerpt for Complete Champion has a PrC that allows you to add 1 to the threat range of a weapon, above and beyond the effects of keen/imp. critical.