These covers are the perfect example of a case of how are these the same book? The US has a light-contemporary feel. The UK has has a vibrant, colorful theme. The US is subdued. The UK is loud. I can't be the only one who thinks it's funny that these represent the same story.
Out of the two, I think I'd have to vote for UK. It looks like it'd be such fun read—it definitely seems like it has a lot going on.
Which one is your favorite?