What is the best weapon in dragon age origins

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.