I have four saves where I play a lot with vampires. Two are stories I'm writing as SimLit as well.
Kassandra - Teen vampire who did not know she was a vampire until she lost control and drank from her best friend. At the urging of her aunt (who is a vampire-human liaison in Forgotten Hollow) she moved to stay with her and is now starting school at a vampire high school (I made my own school, and use Triplis "teens and children quit school" mod and the club system to have a playable school).
Reuben - 400+ year old vampire police detective with a troubled past and personal connections to an even older vampire who is currently a bit of a high society mob boss. He also has an alien roommate he's having trouble getting along with, human apartment neighbors he's also having trouble getting along with, and he secretly also works as a private detective at night (which will get him in trouble at his police job if it's found out).
Victor (aka Mr. R) - He lives in a haunted house, and he occasionally does gig work as a paranormal investigator. There is a human man who is boarding with him that he isn't telling all his secrets too...
Damico - My very first vampire sim. He is an artist who paints and does night-time photography. He's engaged to a human. Currently, I am playing that in order to marry his human fiance, he has get approval from all the senior vampires and the leader of the vampire coven. Not all of them totally approve of the idea of him marrying a human. Also his fiance's best friend doesn't like him. And (pending my purchase of the Werewoves pack) might be a werewolf.
Edit to add a further thought - I think vampires are the most fun to play with when you do a little "world building" in your own head regarding how vampires are seen in that world. Are they completely out in the open members of society? Are they hidden and thought a myth by humans? Are they feared because their blood drinking? Are they admired and respected because of their long lives and acquired wisdom? Do they live among humans? Do they have their own secluded communities and rules? etc. More story ideas may occur if you give them a context to happen in.