The Hobit and LOTR. The Phillip Pullmanโs His Dark Materials. V.C. Andrews (which no one that age should be reading ๐คฆโโ๏ธ). Harry Potter was just taking off when I was that age, too.
of this one series but I remember reading it as a middle schooler in the early-00's and it was about a group of children with supernatural abilities. one girl was telepathic and listened to metal to drown out peoples thoughts, and there were some dark creatures that caused magnetic disturbances (paperclips made a big appearance) and now that I've written it out it sounds quite a bit like stranger things. but also,
Redwall
Captain Underpants
Animorphs
Incarnations of Immortality (which was v much not age appropriate mom what were you thinking)
The Wheel of Time series
The Dark Tower series
I remember Where the Wild Things Are and other art books the most. Reading The Hobbit when I did (9 or 10?) was pretty important to me. A good mix of adventure. I learned to use a dictionary really well because I had never seen many of the words in the book. Growing up in rural eastern Kentucky coal fields I didn't get a lot of help from the adults around me in that regard. I also still remember the feeling of tension and fear in the scenes with the ogres and Gollum having some comedic elements here and there to make being a little afraid fun.
Then I probably got into fantasy novels well above my age shortly after. lol Piers Anthony made several of his books anatomy lessons.