Lynch Heinouson: Psycho Vampire is an extremely black comedy that has received exceptionally good reports from its readers.
It's available from Amazon by clicking on this link.
You can read more about the plot on the Synopsis page, but basically it's the tale of a psychotic serial killer who gets turned into a vampire... and his arch nemesis: Jake Gutt.
The comedy is spread thickly and is very very dark.
Despite being generally unsavoury, the characters are written to be as likable as possible. They may gun hundreds of people down with a mini-gun but they have a really really good reason for doing it.
Click on the links above to read excerpts from the book taken from the early chapters, the middle of the book and from the later chapters. There's also reader reviews, details on the characters and an extended synopsis.