Anything by HP Lovecraft. It's pure horror, though some of his stories may be a bit slow. It would be easy to write about them because they generally contain many short stories. I'm reading about half a dozen right now.
If not, Douglass Adams' series, A Hitchhiker's Guide to the Galaxy, is sheer brilliance. I read them around grade 10 or earlier. They're not hard to get through and won't have you rushing back and forth to the dictionary, and are a pleasure to read.
I'd also recomend the Hobbit. It's shorter and more of a breeze to read through other than the Lord Of The Rings trilogy. I felt it was more action packed than the other books and the story flowed more easier.