Adult

Romance book series are popular among young adult and adult readers. Typically the adult romance series include more graphic tellings of the physical interactions between characters. Romance series usually have happy endings between the romantic main characters but newer series are known to include tragic outcomes.

Christian and religious books are written for those in the Christian faith looking for real life application. These books can be personal stories, testimonies, or applications of Christian principles. Christian fiction is also a popular genre in which Christian principles are incorporated in fictional stories.

Cookbooks typically offer recipes and best practices for specific types of cuisine. Different culinary styles, specialty diets, and celebrity cookbooks are popular cookbooks.

Business books are typically guides for creating or maintaining successful businesses. These books can be about management, marketing, innovation, or nonfictional accounts of those who have experienced success in the business world. The topics business books cover vary as greatly as the experiences of those who author them.

Adult mystery books are crime or suspense novels that remain mysterious until the end. Mystery books are popular among adult readers with many bestselling book series. These books often include murder and serious crime and are usually not appropriate for sensitive readers.

Science fiction books are creative and futuristic novels about time travel, advanced technology, space civilizations, or extraterrestrial life. There are many popular fan favorite books series for adults in the science fiction genre.