The great thing about books is that there is a different book suited for each individual and it can be difficult to give a definitive answer on any given book to read.
One option is to do some research online and find reviews of some of the most popular books that have been released in the past year or two. With a wide variety of genres, there are lots of different books to choose from.
You could also look into some classic books and give them a re-read. Classics like To Kill a Mockingbird, Catcher in the Rye, and 1984 remain popular and timeless even after several decades.
In addition, there are books that have become popular due to an adaptation to film or television. These can be a great way to experience the novel in a new way, by comparing and contrasting the original novel with the adaptation.
Finally, pay attention to award-winning books. There are numerous awards given to novels each year, and these books can be a great place to start when trying to choose what to read in 2019.
No matter what book you choose, the most important thing is to choose something that appeals to your interests. Don't be afraid to explore different genres, authors, and topics to find something that will be enjoyable to you. Reading can be a great way to spend your free time and with so many great books out in the world, you should be able to find something that will keep you entertained!