Asimov, particularly the Foundation & Robot series.

Heinlein, esp. "Something Wicked this Way Comes."

LOTR, every few years.

Dickens, "Tale of Two Cities."

I reread all the previous Harry Potter books every time a new one was to come out. I suppose now that she's finished the series I won't reread them quite as often.

"The age of Innocence," by Edith Wharton

Steinbeck, esp. "The Grapes of Wrath" & "Travels with Charlie."

Anne McCaffrey's "Dragonrider" series as well as any of the harper books.