Technically also a comics fic, but I had to rec it this week because it takes Xander and Dracula onwards from their first meeting, throughout the following seasons. And it's hilarious. Plus, it's all in epistolary format. I love a good correspondence-fic, and this is one. If you're newish to fandom, enjoy! If you remember it from the first time around, reread and enjoy too!
Xander Harris and the Dark Lord: an excruciating correspondence, by
powerofthebook (PG13)