best weapons?

I normally use this guide.

If you don't have black emporium/JoH there is a link to an older version.

There are times that the actual "best" is debatable. Some specs heavily rely on crit chance, and depending on what hilts, etc then the ideal may be different.

Spoiler

If you played the previous Dragon Age games, you may expect Unique purple weapons to be the best, but that is not the case. The best weapons in DA: I are crafted. Although there are plenty of powerful unique items, they pale in comparison to crafted gear.

Unique weapons are certainly very good, but their relatively low item level and lack of customization makes crafted weapons superior at higher levels.

Having said that, let’s take a look at the best weapons for each class, and how you can get them!
Rogue:
Archer:

For archer rogues, the best weapon is Hakkon’s Wrath, crafted via schematic. This bow has a base DPS of 180 if you use a Tier 4 crafting material like Dragon Bone. And that’s not even including the offense slots, the Masterwork material, and the Runes you can insert later.

This schematic can be found in the Old Temple in Frostback Basin by using a Veilfire torch to discover several hidden runes, during or after the “Ameridan’s End” quest.

Next Best Thing: Alternatively, you can also purchase the Bow of the Beresaad bow schematic for 12156 gold from the Black Emporium (if you have a Masterwork Bound Longbow Grip schematic to craft into the Grip slot) or Perseverance, also from the Black Emporium, for 16156 gold.

Dual-Wield:

For dual-wield rogues, the best weapon is the Blade of Red Birth, also purchased from the Black Emporium with a price tag of 8478 gold.

Next best Thing: Hakkon’s Mercy, schematic found in the Old Temple in Frostback Basin by using a Veilfire torch to discover hidden runes.

Mage:
For mages, the Staff of Corruption offers the best combination of highest DPS, ideal slots (all 3 are offense) and the highest number of materials used. This staff can be purchased from the Black Emporium for 16956 gold. It is slightly better than the other Emporium option, Archon Fire Staff, because it has 1 more offense slot instead of a utility slot, giving you a slight damage boost. Next Best Thing: Alternatively you can use the Masterwork Enchanter staff, which can be farmed or purchased from the Black Emporium. This staff has lower DPS and uses fewer materials, but has a grip and blade slot.

Warrior:
Two-handed Weapon:

Axe of the Dragon Hunter is currently the best two-handed weapon in the game by a wide margin. Unlike other high-level schematics, this one allows you to add a Haft and a Pommel to the crafted weapon, significantly increasing its stats. This axe can be bought from the Black Emporium for 15356 gold.

Next Best Thing: Sulevin Blade schematic (sold at Black Emporium for 16956 gold), followed by Hakkon’s Valor, found in the Old Temple in Frostback Basin by using a Veilfire torch to discover hidden runes.

One-handed weapon:

This was the hardest weapon to figure out, because tank one-handers are all over the place both in terms of their DPS and ideal slot types (offense,defense, etc). In the end though, I believe the Mortalitasi Firm Club is the best. Although all 3 of its slots are offense (not ideal for tanking), you can still make good use of them by stacking 3 % stagger on hit materials, which will give your tank’s attacks a chance to stun the target, which is pretty useful for tanking things.

This mace can be bought from the Black Emporium for 6078 gold.

Next Best Thing: Hakkon’s Honor schematic, found in the Old Temple in Frostback Basin by using a Veilfire torch to discover hidden runes. This weapon has significantly lower DPS, however it does have higher number of materials per slot, and of course its free!

Shield:

The Masterwork Grey Warden Shield is the clear winner with the highest possible armor rating in the game as well as two defense slots. The schematic can be purchased in Frostback Basin’s Stone-Bear Hold.

Next Best Thing: the three shield schematics purchasable from the Black Emporium, with a cost of 3273 gold each.

As a final note, acquiring these weapon schematics is only half the story. You then need to craft them with proper materials to get the best possible result. There are 3 key tips for crafting your weapons:

Use Tier 4 crafting materials (Dragon Bone, Dragon Scales, Dragon Webbing, etc ) for the highest stat numbers, ESPECIALLY for the Damage/Armor slot to get the highest possible DPS/Armor.

Choose the appropriate materials for your particular character. For example, if you are crafting a DPS weapon, you will usually want to stack stats like + % attack and + critical strike chance, and the appropriate Masterwork.

Extra crafting components like Runes and weapon grips also have a tier system, so try to craft the best possible version to make your tier 3 weapon even more powerful. Schematics for these are often sold by merchants or found in the game world.

Runes alone give you tons of customization and ways to make your crafted weapon even better.