The weapon I got the most use out of on my old character was a Blades Sword named Turmoil, which had a base damage of 101 and dealt 69 points of fire and shock damage each hit. Very quickly disposed of my enemies. I was playing on Legendary though, so I needed all the extra damage I could get.
I have no idea why but I love Dawnbreaker a little too much. Other than that, there's Auriel's Bow and the Nordic set, a few of the Ebony weapons (Definately not the 1H Sword or Dagger...), and if some of the Dragonbone weapons weren't so jagged I'd definitely use them more often.
I've got to echo Vileo on pretty much every point. Dawnbreaker's awesome, Auriel's bow with both it's effects is awesome, Nordic weapons are great. I also really love the aesthetic of the Forsworn Sword. Crossbows are definitely high on my list, too. But yeah, Dawnbreaker definitely tops the list for me.