With the benefits of frost resistance: Nord But if your going for a unique vampire experience with a unusual race I would go with either a Orc or a Khajjit or Argonian. P.S Khajiit get saber cat like fangs as vamps and the Scaley ones get longer fangs as well and their scales change and go darker. Hope this helped!
Dunmer are perfect candidates in terms of mechanics because their fire resistance offsets the vampire weakness. In a roleplaying sense, they also will blend in as dunmer often are pale with red eyes.
Personally I prefer the look of imperial or breton vampires. Nords are too big.