Me and one of my best mates had a nice long discussion about this after finishing up trivia one night. And come up with the following concept about vampires.
Vampires herald from Europe. So this is where the highest concentration of "real" Vampires would be. These vampires are completely arrogant and self absorbed by nature, not because they think they are better then people, but because they know they are better then people. They are quite literally the top of the food chain.
Vampires interact almost solely with other Vampires, everything else is below them. As vampires live for ever, all vampires are masters of pretty much every single language imaginable (after all, what else are you going to do with your spare time but learn new things) They also dedicate themselves to all forms of creative art, painting, writing, music.
Vampires live in small communities located in houses that would hold something of a "Heritage" status. (The buildings that are immensely old, or have amazing historical significance) But these small communities of Vampires keep in constant communication with each other, always by written letter (they are just sticklers for tradition)
Vampires are beautiful, but in all sorts of different ways. Some, in a raw, overpowering manner. Others, in a refined control way. No two vampires look the same, but each and everyone of them is a figure of lust too humans. Even if their appearance isn't what you would normally go for, if you were too see one on the street you would still turn your head to look a second time. To aid there amazing beauty vampires are impeccably dressed, all the time. Always wearing the most expensive of hand tailored suits and dresses.
Although Vampires know humans are below them. They are also aware of the usefulness of said humans. And so Vampires are not above utilizing human services to further there own means, or make their own lives easier, thus leaving more time to keep studying and refining there own arts.
Vampires feed on humans. They have too. Its there only for of sustenance. But they are very selective about how they do this. After all, no one wants to go back to the days when humans tried to hunt and kill them. That was such an inconvenience. So they are careful about how, where, and when they feed. Making sure to pick victims that wont be missed, or easily traced back to them. When they feed it is normally done as delicately as possible, ensuring that no blood is spilled on there immaculate outfits. However some Vampires have been known to give themselves over to the blood lust as they feed, and subsequently turn the feeding into a blood orgy. Generally these Vampires will punish themselves with some form of repentance for a few hundred years, after all. No one wants to be seen in such a primitive state.
Vampires VERY rarely turn humans. Its just unheard off. Humans are so.. common. However occasionally a human will capture a Vampires eye, maybe because of a position of power they hold. Maybe they have shown particular traits that are desirable. If a Vampire believes that a human is worth turning, he will meet with the other Vampires from its place of residence and they will watch the human. All of them. If a majority of the Vampires in the residence agree that the human is worth turning, then the human shall be turned. This period of assessment can last a humans entire lifespan. After all, for the ageless vampires its just the blink of an eye. No human below the age of 30 will EVER be turned. They just don't have the maturity to deal with it.
Vampires take human lovers, but only on small fancies. It is unheard of for a Vampire to actually desire a human.. they are so common. But taking human lovers is completely acceptable. Feeding of a love after taking them is quite commonplace. After all, no human is worth having more then once.. there are just so many more out there to chose from.
The Vampires are incredibly powerful. Super strength, super agility, complete nocturnal vision, quick healing capabilities (relatively) and never die of old age (they are undead) They are almost immune to all virus' bacteria, and germ's (again, undead) But its a common misconception that vampires can only be killed by steaks, garlic, and decapitation. Any amount of serious trauma will end a Vampires life. But it does need to be serious trauma.
Vampires regulate there own ranks, as they know no other force in the world is capable of doing it. Any Vampire that breaks the Vampire code (such as turning some one without a residences consent. Or turning some one below the age threshold. Or worse of all, falling in love with a human) Will be hunted down, and killed by his fellow peers. Generally such a task will only be given to one or two of the strongest Vampires in a residency, but its a task they will take on with complete and utter efficiency. A Vampire sent out on a hunt cannot return until his query is killed. Fights between Vampires are displays of amazing martial prowess. Every single vampire is a master in at least one form of weapon. So when they fight battles are displays of skill and finesse. Only one Vampire will ever walk away from a fight like this. No quarter is given. Ever.
There is more.. but that's the gist of it.. Man, we put way too much thought into that.. but to be fair.. it was while we were coming up with an idea for a T.V show.