Can I pick a few?

Obviously
Middle-EarthJ.R.R. Tolkien's books such as
The Hobbit and Lord of the Rings made my childhood.
Oh, and Frodo is my muffin in this journey <3
One of the greatest world builders in my opinion.

Second place, but strangely close is
Caligo or The First WorldH.S. Crow's world building is seriously on a level that I haven't seen in modern authors. It's detailed and rich, and he's challenging Tolkien in my opinion by bringing every mythos from every culture across the world to life, and utterly it's creative... not some rip off... I got a chance to read this author's sample of the Oathkeeper series coming out in Winter and it nearly made me want to steal his manuscript. (Met him at Supercon where he was helping Zach from Steven Universe... I was getting autographs and that's where i learned about him and found out what he had done.) Enough said, meeting him in person and getting a copy of his first book
Lunora and the Monster King made my day, and even till now I'm still thinking about his world and the books. He's pretty poetic and passionate about his work. Below I placed the map of the Kingdom of Nevermore, a tiny fragment of the world he created and the main area of the first book he released.

Last world,
Hogwarts!!!
From Harry Potter by J.K. Rowling ^_^
Exploring those corridors filled with magick and unknowns alongside other students just sounds fun and gives me that good ole days feeling.
