Procrastination Nation

Why not both?

Because the original question was specifically about preference, but 'both' is a perfectly acceptable answer. I'm not some sort of boner cop or erotic magistrate - liking them equally is fine!

I'm bisexual

Again, that's fine, me too, although vampire/werewolf is not traditionally the dichotomy that refers to.

Couldn't be werewolves, I'm not a furry

I see the confusion there, but while they do have fur I'd draw a (admittedly blurry) line between a werewolf fantasy and a furry wolf fantasy. Werewolves have a much older, much deeper mythological root and have always been about the suppressed savagery within mankind, which I would say makes them their own distinct thing.

Neither, I don't want to have sex with an animal or a corpse

Then great news: vampires and werewolves aren't real. But this isn't about what the theoretical reality of how such beings would exist in the mundane world, this is about the psychological core of their respective sexual fantasies.

What about dragons?

What about them? The question was about vamps and werewolves. Besides, while there is some overlap, I'd say a dragon fantasy is usually its own distinct thing and more about majesty and magic.

This answer is only for subs/bottoms!

So, from what I've seen, the majority of such fantasies are from the perspective of being, shall we say, "acted upon" by monstrosity, so that was the audience I was primarily addressing. I will grant, however, there is a strong contingent of those whose fantasies are instead about dominating the monstrous. In these cases, the metaphorical core remains the same - the vampire still represents a dark grace and refinement, while the werewolf is bestial force - the question is which would you prefer to break? Would you rather chasten beautiful wickedness or tame brute ferocity?

But what about your preferences!?