If you're a John Green fan (and there seems to be a lot of those out there) this should be a book you can recognize easily. One thing I really like is that, even while these covers are completely different in style, they both have the dramatic black background. Individually, I don't like the US cover too much—it's a little dull for my taste. Even though the UK cover is similarly simplistic, it's definitely my favorite of the two.
Which is your favorite?