If you like Diary of a Wimpy Kid, try Dork Diaries, Dear Dumb Diary, the Amelia series, Big Nate series, Notes from a Totally Lame Vampire.
If you like The Iron King, try Stolen Away, Firelight.
If you like Hatchet, try Hero, Woods Runner, Fourmile, Surrounded by sharks
If you like The Hunger Games, try The Always War, The Eleventh Plague, and Witch & Wizard.
If you like Maze Runner, try Undertow, Eleventh Plague, Sylo.