Well, Vampire is one underestimated RP. I believe you would love the setting of Vampire:The Dark Ages even more, as it's historically as accurate as possible, with a flair of vampire charm (imagine Interview with the Vampire and you'll get the picture!)
I'm not really a fan of Bloodlines, to me it felt as if White Wolf just aborted the game after not making the amount of money they were expecting to. There are books from the Masquerade that you can read. To be more exact, there is a series of 13 books, each book specializing in one of the 13 clans, all written to follow up to their previous and set the background for the next one. The series starts with the Toreador book [link] As for the Dark Ages one, I think there is only the players handbook for the tabletop game printed, along with a couple of supplements.