Whatever catches your fancy:
Charlotte Bronte: Jane Eyre
Emily Bronte: Wuthering Heights
Austen: Pride and Prejudice, Emma, Persuasion
George Eliot: Middlemarch
Dostoevsky: Crime and Punishment, Bros. Karamazov
Tolstoy: Anna Karenina, War and Peace
Proust: Remembrance of Things Past
Faulkner: Absalom, Absalom
Joyce: short story The Dead, Portrait of the Artist as a Young Man, Ulysses
Thomas Mann: The Magic Mountain
Virginia Woolf: Mrs. Dalloway
Nabokov: Lolita
Graham Greene: The End of the Affair
Joseph Heller: Catch 22
Ayn Rand's The Fountainhead and Salinger's Catcher in the Rye and Nine Stories if you haven't read in high school.
anything by Joan Didion (nonfiction) could start with The Year of Magical Thinking or essay Goodbye to All That
Philip Roth: Goodbye Columbus
Toni Morrison: Beloved
John Kennedy Toole: A Confederacy of Dunces
David Foster Wallace: (nonfiction) any essay on cruises or tennis
Jonathan Franzen: The Corrections
Michael Chabon: Wonder Boys
Ian McEwan: Atonement
Murukami: WHAT I TALK ABOUT WHEN I TALK ABOUT RUNNING
The Wind-Up Bird Chronicles
Hallfor Laxness: Independent People
Elena Ferrante: the Neapolitan books, starting with My Brilliant Friend
Karl Knausgard: My Struggle