(and yes, there are plenty of other legendary swords and weapons of both Western and Eastern culture that likely informed classic and modern fantasy writing and gaming).
We've got swords made with relics from dead saints, a sword broken/blessed by an angel, a lance that killed a dragon (or Wyrm), and a spear used to kill a god (or son of a god, depending on how one interprets their Trinity). If those qualities don't score you at least a +1 for your weapon, I don't know what will...
Partial list of "super bad ass Catholic weapons"
Ascalon (or Ashkalon)
Sword of Mercy
More on Longinus
Of course, there are a few "Spears of Destiny"