Sten's sword is pretty good (the one you get from doing Sten's sidequest)
but there are even better 2 handed weapons. I can't remember their names though. I know Sten's sword has an attack power of about 12. Some of the 2-handers I've found have 15 attack power, along with stat boosts and open enchantment slots.
They used to talk about us you know... Xbox Live GT: Unknown3790
Starfang sword from the Super Metal random encouner is the best 2h sword in the game. It's tier 8, even higher than Dragonbone. You need Warden's Keep DLC for it.
You get a random encounter with a superman-esque scene. There is a crater. Take the ore from the crater to the smith in Warden's keep ( after finishing it's storyline ) and he will give you the choice of crafting either a greatsword or 1-handed sword.