To see the all the details on what books the cool kids are spending their money on these days, check out the video above, courtesy of Coinage, Time Inc.’s personal finance video company. It’s no surprise that J.K. Filling out the top five of YA fiction bestsellers are the Twilight trilogy, Fear Street (R.L. Show Full Article Stine hasn’t lost his touch), The Hunger Games trilogy, and finally the Shadowhunter Chronicles. The young adult fiction genre is off the charts in terms of popularity right now and sales have risen by 40 percent over the last decade. Rowling’s Harry Potter series leads the pack with $504 million in sales.