When I first heard about Christopher Farnsworth's novel, Blood Oath, I was intrigued but skeptical. Turns out I needn't have worried; Blood Oath was awesome. The gist of the story is that a vampire - pardoned from execution by President Andrew Jackson in the early 1800s - has been secretly working for the White House ever since, defending the President and the country from domestic, international, and supernatural threats. It's National Treasure meets Men in Black meets... I dunno, Batman? The X-Files?
And it TOTALLY works. The action keeps you turning the pages. The characters aren't the most rounded you'll ever encounter, but then again, it's an adventure novel, not a character study. It is well-written and well-researched, stuffed with fantastic little historical notes that are accurate and intriguing but not boring or plot-halting. (You know - the kind where you accidentally learn something while having fun.) The neat thing about this book is that you can enjoy it even if you don't read "vampire books" - and you can enjoy it if vampire books are your favorite type of literature. If you're interested in American history... if you're interested in the secret service or how we deal with domestic terrorism... if you're interested in old school horror movies and movie monsters (specifically Frankenstein and his monster, both of whom play an important role in this book)... if you like your heroes tall, pale, and bloodthirsty... then I think you just might love this book.
And the sequel (there are two books in print right now, another on the way, and a full series planned) apparently involves Osama bin Laden as some sort of demon that the vampire hunts and kills. Just, y'know, for what it's worth. :)