My first topic is one which may be slightly overdone but there is a lot of lore surrounding it.
Most cultures have legend about vampires, but they do vary a bit.
Where there is the glorified Hollywood version with it's sexy allure, the legend of the vampire has been commercialized to appeal to a broad viewing market. In other words, it's been warped from something that used to be genuinely feared into something of curiosity.
It's well known that there are several movies and novels revolving around this legend, and most of them contort the legends too.
One of the few things that relates all the legends to do with vampires is their need to feed on blood. Even sunlight isn't a sole problem in all the lore. Speed, strength and an amazing ability to heal are common attributes given to such a creature, but again, it's not the same in all legends.
Within Romanian mythology vampires are known as Strigoi. These are considered as troubled spirits that are rising from their graves, but they can also be living people. With this lore they are seen as immortal.
Whether you prefer the Hollywood version or the more traditional thoughts, the legend of the vampire is wide spread and well known. Many think they know exactly what a vampire is but never spare a thought for the origin of the idea.