If you like The Clique by Lisi Harrison, then try The Girls by Amy Goldman Koss.
If you like Eragon by Christopher Paolini, then try The NeverEnding Story by Michael Ende. Then watch the movie The NeverEnding Story. (Note: There have been multiple films and shows made based on TNES. The first film was the best, in my opinion, and the truest to the book.)
If you like Inkheart by Cornelia Funke, then try Poison by Chris Wooding.
If you like Hatchet by Gary Paulsen, then try Call of the Wild by Jack London.
If you like The Bartimaeus Trilogy by Jonathan Stroud, then try His Dark Materials trilogy by Philip Pullman.
If you like Al Capone Does My Shirts by Gennifer Choldenko, then try Tru Confessions by Janet Tashjian.
If you like The Gospel According to Larry and the other Larry books by Janet Tashjian, then try Nothing But the Truth by Avi.
If you watched the TV show Life with Derek, then read Who Put That Hair in My Toothbrush? by Jerry Spinelli.
If you watched the TV show Phil of the Future, then read I Was a Teenage Popsicle by Bev Katz Rosenbaum.
If you want additional recommendations, leave a comment below.
Similar booklists: If Then for Teens and If Then for Elementary School