The most powerful sword is the Ebony blade by far, it dosent do much but with it, you are absolutly unable to die, every sucessful hit drains the life from the target healing you and dealing extra dmg... I LIKE PIE!
Daedric, for all three.
The Master Sword.
The Cronicle 2 Sword is the most powerful sword in the game.
The most powerful sword in the Zelda series is the Master sword. This in game weapon is said to have hidden secrets and only the chosen characters are able to wield it.
Tiatenzoa
the variations of the big goron sword
The most powerful sword in the video game 'Final Fantasy' was the Ragnarok sword that was featured in the 'Final Fantasy Tactics A2:Grimoire of the Rift' game.
the level 20 default sword is probly the most powerful
Onyx Sword from Onyx Giant. If your talking about the Ps2 version. (Yes, the onyx sword is the most powerful sword in Easy, Medium, Hard levels of the game but not in Extreme mode on the PS2 console.)
The cumberland sword. It is very rare and hard to find.
there is the master sword and that is the best sword in the game. (it should have been the best in every game because it is the sword that is evils bane but apparently some rocking eating monsters can make a better one!)
Console command, or even better yet, Pick up the sword and drop it in the Jarls quarters.
I think the most powerful weapon in Skyrim is Daedric Weapon. You can make this by having 90 on skills on smithing and you have to collect a deadric heart and also a couple of leather strips and also a couple of Ebony Ingrots then go to Whiterun and Blacksmith Forge (Located the shop on the right).Hope this helps :)