Lord of the Rings series, Hobbit, Peter Pan, Narnia are some of the books that I read aloud to my son at that age.

Though not "adult" literature, another series that we did before that was Frank Baum's Wizard of Oz series. We also did all the follow-up books to the Oz series which were a lot at that time. My son was very impressed with Dorothy and friends and wanted me to read as many stories of them as possible.