Vanilla skyrim vampires have pale skin and red and black eyes and less unique looking faces.
Volkihar Vampires (new type of vampire added in Dawnguard) have gold/amber glowing eyes (depends on the lighting, I'd say they are gold but people swear they are amber), gaunt faces and look very dead compared to the vanilla skyrim vampires...and of course unlike the lesser Skyrim vampires the Volkihar can turn into the vampire lord form.