Dracula by Bram Stoker. This is the granddaddy of the all. While there were earlier novels, this is the one that set the standard for all that followed. It is an interesting story with great characters written in an engaging epistolary form. If you have only seen the movies, don't think you know the story (especially if your knowledge is based on the woefully mis-titled Bram Stoker's Dracula.)
Read the book.
'salem's Lot by Stephen King. Not only is this a great vampire novel that I have read more times than I can remember, it is among King's best despite its pretentious 70s style. King himself envisioned it as a modern Dracula. It certainly lives up to that vision and is even scarier than the original. (When I first read it in 1979, I started the book at 7:00 pm and finished it at 4:00 am the next morning. I waited until the sun rose to go to sleep.) The confrontation between the vampire Barlow and the alcoholic priest Calahan is a classic as is the revenge of the town children on the mean bus driver.
Vampire$ by John Steakley. This is a fun book that will keep you on the edge of your seat. The hunters include a young priest and a former pro-football player headed up by a former government operative named Jack Crow. And get this, they work for the Vatican and the Church is presented in a positive and respectful light. The vampires are thoroughly evil and nasty. (We even learn that vamps love opera and hate rock-n-roll. Lots of great characters in here. A good vampire novel has to have good characters. Don't judge this book by the John Carpenter movie based on it. (Does Carpenter hate the Church and priests or is it just me?)
They Thirst by Robert McCammon. Picture 'salem's Lot on steroids. This time the vamps take over Los Angeles. One complaint; if one is going to include the Church in a book, it helps to do research so that you get the terminology right. Crosses and crucifixes are not the same thing. Alas, this has been out of print for several years.
I Am Legend by Richard Matheson. All the movie adaptations have been good ( I am a big Omega Man fan--Chuck Heston and machine guns!) but the book is so much better.