Science Fiction, also known as Sci-Fi, books' stories are mostly based on futuristic technology/robots, aliens, and/or unknown entities. Two of my favorite Sci-Fi authors are Pittacus Lore and James Dashner.
James Frey is better known as Pittacus Lore. He is the author of the book I Am Number Four. I Am Number Four is part of The Lorien Legacies series. I Am Number Four was made into a movie in 2010. My advice is to read the book before seeing the movie considering that the movie lacked half of the main information that was present in the book.
James Dashner has written several books including: The Maze Runner, The Mortality Doctrine, and The 13th Reality. He was awarded the 2008: Whitney Award for Best Youth Fiction, 2011: ALA Best Fiction for Young Adults, and 2012: Young Reader's Choice Award for intermediate grades.