Dawnbreaker, the others I tried but never really took to. I used Ebony Mail and Blade for a while with a darker character, but that guy was a kind of Daedric kind of fella so I stuck with that.
Dawnbreaker kind of surprised me, I knew that it had a bonus against the undead and that there was a fiery explosion as part of the deal but as a stealth character the lit up cross guard seemed a bit much.
Using it instead of reading about it were two different things, the fiery explosion in a dark somber crypt was spectacular. "Holy $%^& !!!!" Sound design is important to me so the crackle of the explosion was very cool, and the ethereal blue flame rippling outwards was pretty impressive too.
I had a great big grin, and I started running through the crypt looking for more Draugr to smite. Definitely changed the way I approached dungeons, instead of sneaking about and sniping from the dark I strode in bee-lining for any Draugr in the room.