I love both of these covers, even though the US one is quite funny with all the make-up the model is wearing. I think she looks great, though, and it makes the book look badass (which I'm sure it is - I need to catch up with this series!). I like that the series name is included on the top right of the cover, and the translucent title text is pretty cool.
I think the UK just wins it for me. I've always been fond of the general design and title fonts used, and I like the images always included in the background. Very fitting for a zombie novel, don't you think? Also the colour is very in your face, hard to miss on a shelf, which is always a good thing.
What do you think?