What are your darlings reading? My upper grade students are going crazy over John Flanagan's Ranger Apprentice Series. I just finished reading his Brotherhood Chronicles. The kids are going to love them too! If you students like Tolkien (fantasy) but find him hard to follow, they will love John Flanagan's books.
Of course Diary of the Wimpy Kid, Twilight, and Hunger Games are also very popular series.
My middle grade students found my "You wouldn't want to be...." series. They are written by different authors in graphic novel format about historical events. This is a great way to get students to read history.