The one you enchant :D
Well, of non enchanted, probably daedric (ware axe , ware hammer...)
And of uniques one,
If you want statistics, the one that does the most dmg is one of those darts you get from
Black dart gang, thinks it's called something like spring dart or maybe with one more
prefix, not sure, in the sewers of Mournhold. Also stendar's hammer (also from Mournhold,
but you have to steal it, and it weights 1000 so you can't wear it unless you cheat, which
kills the fun).
Also, bipolar blade and trueflame and hopesfire. If you're unlucky and don't have the
Tribunal expansion, sunder is probably the strongest unique.

You can also be a slimy cheater and make yourself obliterating weapon in construction set.

Cheers
Chaka

The best one is your character cause all you have to do is use the console and give urself
monster strength and hand to hand!