...vampires are akin (at least in my mind) to the perfection of the human race. Barring of course the daylight problem. Powerful, sexy, immortal, wise (in most cases) and hidden away from everyone's view. The possibilities alone, I think, is the majority of the mystique and allure.
Of course, like humans, there are good and bad vampires. But I prefer to mostly focus on the good. Though, personally, I wouldn't have a problem 'feeding' or farming hemoslugs. So I might border in between good and bad, right and wrong. It's all just dependent on each person's point of view anyway - 'good' and 'bad'. My 'bad' may be someone else's 'neutral' or even 'good'. And vice versa. But, with all of eternity to work it out, who cares? At the end of all things, we're all unique anyway. And there's nothing that can change that. At the same time, we're all somehow intertwined. Though the exact connections are often lost on me, I'm sure with enough time, I could sort it out.
Again, I think it's the limitless possibilities that draw me in.