Where to begin...hmm...
Great Expectations - Charles Dickens
Anna Karenina - Leo Tolstoy
Night - Eli Weisel
A Farewell to Arms - Hemmingway
Short stories and essay's are always good, too, for when I want to be reading something, but don't have the time for a novel.
Spoon River Anthology - Edgar Lee Masters
As I Lay Here Dying - William Faulkner
The Meaning of Life (this was an academic book from a philosophy class I took. I don't know the author).
Harrison Bergeron - Kurt Vonnegut
The Lottery - Shirley Johnson
Young Goodman Brown - Nathaniel Hawthorne
That's all I can think of for now.