Sigh Vampire craze, I love me some vamps, but I don't believe twilight or true blood started this craze I think vampires were bought into the mainstream and made cool (for our generation anyways) by Blade back in 1998, as soon as blade hit thats when all these books/tv shows/films made an appearance. For example, Hellsing, Underworld and Twilight all were released off the success of the Blade series I can't think of any other quite so well liked vamp films prior to this apart from the lost boys and From Dawn to Dusk, but they never co-existed with humans
Alot of them follow the same plot line as blade as well.
Civilizations of vampires co-existing with humans but theres always a trouble maker and theres always a human/vampire (sympathetic towards humans) to sort it out, In blade it was obviously blade, in twilight it was the main vampire (robert patterson) sticking up for bella and in true blood it was bill compton who helped sookie and friends against vampires and other demonic characters alike.
Now I know vamps have been around in the media since Nosferatou, but for this generation I think Blade sparked the craze.
Plus the last episode of true blood was rubbish, they had a 12 episode quota, but wrapped the season up in 11 episodes, the last episode was a drag out episode, alot of it could have been resolved in episode 11, but they needed something to meet the 12 episode quota so dragged out and closed alot of the sub plots