I've been enjoying Scott Westerfeld's Leviathan trilogy (not quite as much as his Uglies series, though) and the final book, Goliath here, just came out. I really enjoyed it and thought it was a nice, fitting ending. (Much better than Dashner's The Death Cure *see below.) Not every plot line was tied in a nice, neat little bow, but there was lots of resolution and some very nice romantic elements. This entire series is well worth a read. I enjoyed my first introduction to steampunk and I think Scott Westerfeld is a fantastic writer. Great book!
