What is the most powerful weapon in Dragon Age Origins Without DLC?

Answer 1

some weapons have damage bonuses to certain types of enemies or magic bonuses such as extra fire damage, but in terms of just straight up damage, most powerful weapon (not including any DLC) is the greatsword Ageless.

Answer 2

it all depends on what type of character you have

for a warrior you can have dual wielding, 2h and weapon and shield

dual wielding i would recommend keening blade or topsiders honor, if you have dlc i would recommend starfang

2h depends on if you like swords, axes or hammers, for swords, i would recommend starfang(you can get 2h version) or the summer sword, for axes probably the biteback axe obtained by killing the high dragon and for hammers i would go for chasind great maul. keep in mind the chasind great maul has 14.4 damgage but also has a +5 damage bonus making it the best 2h weapon with its high armour penetration.