Alright, my favourite author is Terry Pratchett, but I'm going to ignore the Discworld series because if I did the top three books would all be from there...
As it is, that makes my top three all from Kim Newman's Anno Dracula series! In order:
1. The Bloody Red Baron - the second book in the series
2. The Judgement of Tears - the third book in the series
3. Anno Dracula - the first book in the series
All awesome books. Anno Dracula is set in 1888, three years after Dracula triumped over his attackers. Now married to Queen Victoria, with a good chunk of England's population turned into vampires, the undead across the world have come out of hiding. Many have made their way to England to join in Dracula's new world order, but immortality is being embraced across the world.
Then, in 1888, in the streets of Whitechapel, someone begins to murder vampire prostitutes, carving them up in a truly gruesome display. So yeah, the alternative title of the book could very easily be, "Jack the Ripper: Vampire Slayer". Fascinating books, with some pretty unique takes on vampires. Not to mention cameo appearances by a whole swathe of characters in the public domain. Professor Moriarty comes in at one point, the master of the Tower of London is Count Orlock, the coroners on the Jack the Ripper case are Doctors Jekyll and Moreau, not to mention a raft of historical figures as well.
The sequel, The Bloody Red Baron, is my favourite. Set during 1918 in the days leading up to Germany's last big offensive, it mostly concerns itself with the Baron Mannfred von Richtofen, more commonly known as the Red Baron, one of Germany's flying aces with the ability to shapeshift into a giant bat-thing and tackle planes in mid-air. The other prominent characters include a squad of Allied flyers tasked to bring him down, Edgar Poe, living in exile in Austria, who is called in to write the Red Baron's biography, and a number of characters from the first book. If you thought the first book was gory, well... it seems as if Kim Newman decided to use the resilence of vampires to subject them to as many agony as was inhumanly possible. Still, great book.
The third book is the Judgement of Tears, which is hard to talk about if you haven't read the first two. It's set in Rome during the 1960s and is mostly about wrapping up a lot of the major themes built up during the first two books. I really like it, because it basically highlights all the things I find amazing about Kim Newman's take on vampires.
Great series, and Kim Newman is writing a new one (called Johnny Alucard, set in the 1980s), which I believe is set to come out this year (coinciding with the 20th anniversary of the release of the original book). I heartily recommend them to anyone who... well, anyone really. The series has some of the most interesting takes on vampires that I've ever seen. The books are pretty messy and probably not for the squeamish, but hey, that could be a selling point for a lot of people.