Now this has possibly been discussed or used already and I apologise if this upsets anyone for rehashing it and putting it forth as mine.
In Buffy versus Dracula Anya is very taken with his power and his looks, implying she has met him before. I am going on memory here so I could be wrong. Consider it an AU if I am ;).
My challenge or discussion topic is this:
Everything occurs as it did in canon.
What happens is around the episode events.
Knowing he would eventually reach Sunnydale in the next few years, Anya 'trains' Xander to be an ideal companion for Dracula.
Even caring for Xander, she still wants her powers back as a demon more and knows Dracula when he arrives is a means of getting her powers back.
Knowing just when Dracula is going to be in Sunnydale she contacts him to make a deal. Having seen Xander earlier, Dracula agrees. Soon after the episode finishes Dracula gets control of Xander again and he leaves.
Anya gains her powers back and Xander becomes the Consort of Dracula.
I admit, I'd like to see these guys together, so please let me know if you know of any stories or you decide to write this yourself.
Xandria