In no particular order, here are some books with fantastic worlds to explore.
Shade’s Children by Garth Nix
Here’s a YA book with a dark sci-fi and fantasy atmosphere. Think of some of the best dystopian/sci-fi novels meeting Frankenstein, and you’ll have this masterpiece.
Daughter of Smoke and Bone trilogy by Laini Taylor
A war-torn fantasy world, populated with chimaera and angels, bent on the opposing side’s destruction. The setting is one of the trilogy’s strongest points (and let me tell you, it has a lot), and added to the mood throughout the novels. SPOILER (maybe, kinda, sorta). There is one scene, where a character is being tortured by the enemy in the scene of a battle amidst his slaughtered comrades, and the description of the events beforehand, and also the overall area add so much to a scene that already had me in emotional turmoil. The entire world really just adds to everything, characters, scenes, all of it.
Harry Potter series by J. K. Rowling (Come on, guys, this had to be on here)
What can I say? The wizarding world has been with me since elementary school.
Good Omens by Neil Gaiman and Terry Pratchett
This one is a bit different, but it does and excellent job of weaving gothic/fantasy elements into the “regular world.” It’s one of my favorite stand-alone books, and a must read for everyone. I absolutely adore it, and I will never give up hoping for a movie.
The Sword of Truth by Terry Goodkind (Seriously, this man is a genius)
The series itself is huge, and it has a land to match its gigantic proportions. I marathoned it in a few months, and honestly, I still think about what goes on in that world sometimes. It’s one of those places that makes you want to just keep reading about it, and I am seriously regretting reading it so quickly. I need to reread it some day.