US // UK
It's no contest for me this week: I LOVE the UK cover. In my opinion, the US one doesn't look YA enough, and it just isn't making me want to read the book. I like how it's trying to illustrate the historical element of the story, but I don't think it works.
Now the UK cover is one I would rush out and buy. The image is clean and incredibly eye-catching, and the title/author name font go together so well with the black and red colour contrast. It conveys history and time, but uses a much more subtle approach. It's one of my favourite covers of the year so far!