Depends on what you are looking for in a thrall, melee vs magic specifically. I'd vote VV x2 of the available options but 2nd the poster who suggested briarheart. Give a dual wielding BH two enchanted swords and they'll wreck shop. --- It's better to regret the things you did than the things you didn't do.
Orchendor I believe? Yes, I havent encountered him yet but he would be a candidate also.
As of right now I have a Master Vampire and a Volkihar Vampire thralled. The Caller is chillen on my floor in Whiterun. (Where should I get my perma-house by the way? any suggestions?) --- :u with love, FrOzEnFlAmE811