The first of Philip Reeve's prequels to the "Hungry Cities" books for young adults is Fever Crumb; the same would also enjoy Ian McDonald's Planesrunner. The Chris Wooding "Tales of the Ketty Jay" series (steampunk Firefly, kind of) starts with Retribution Falls, and the most recent of the Joe Abercrombie books is The Heroes. We also liked Ex-Heroes, a superheroes-vs-zombies story, and Bitter Seeds. I really liked Felix Gilman's Thunderer, but found the sequel slow and complicated; The Half-Made World (same author) was another good read, but the sequel isn't out yet. Wouldn't recommend Grossman's The Magicians unless you like whiny, self-pitying protagonists; Bacigalupi's The Windup Girl, Hugh Howey's Wool, and Ian McDonald's The Dervish House are all much better reads.