Gaming Universes

Teyvat (Genshin Impact)
The Continent (The Witcher)
Hyrule (The Legend of Zelda)
Tamriel (The Elder Scrolls)
Thedas (Dragon Age)

Literary Universes

Middle-earth (The Lord of the Rings/The Hobbit)
Hogwarts and the Wizarding World (Harry Potter)
Narnia (The Chronicles of Narnia)
The Wheel of Time World (The Wheel of Time)
Prythian (A Court of Thorns and Roses series by Sarah J. Maas)
Erilea (Throne of Glass series by Sarah J. Maas)
Crescent City (House of Earth and Blood series by Sarah J. Maas)
Ixia and Sitia (The Chronicles of Ixia by Maria V. Snyder)

Sci-Fi Universes

The Star Wars Galaxy
The Star Trek Universe
Mass Effect Universe

Other Fantasy and Adventure Universes

The MCU (Marvel Cinematic Universe)
The DC Universe

Anime & Manga Universes

Amestris (Fullmetal Alchemist)
The Pokémon World
Violet Evergarden
No Game No Life
Frieren