I, Zombie [http://www.amazon.com/TOMES-DEAD-ZOMBIE-Tomes-Abaddon/dp/1905437722/ref=sr_1_6?s=books&ie=UTF8&qid=1319811181&sr=1-6] by Al Ewing is a really good piece of Zombie fiction.
I don't want to spoil the plot by giving too much away, but it's a really interesting take on the genre.
It's told from the point of view of the protagonist who is a Zombie that has walked the Earth since the Dawn of Man, and every couple of chapters there's an interesting flashback to his life as he participated in different eras of history (a bit like the flashback in Highlander).
Then Part 2 happens and holy shit, the story takes an epic turn that you wouldn't expect from a book about Zombies and all sorts of hell breaks loose... it's at this point, when you can start to put all the pieces together, that you realise what a brilliant take on the genre and true nature of zombies this story really is.
I can't recommend it enough and not any more thoroughly without spoiling the plot, but you should check it out if you can obtain it for a reasonable price.
In fact, every book I've read in the Tomes of the Dead series by Abbaddon Books have been great pieces of Zombie fiction, from the British Gangster themed The Words Of Their Roaring to the epic historical romp The Devil's Plague has been good pieces of Zombie fiction... albeit somewhat pulpy, but enjoyable nevertheless.