Little Women, but you've probably already read that. If you've read Jane Eyre, you should also read Wide Sargasso Sea (the story of the mad woman in the attic), which is not a classic, but is a well written prequel. Then there is Lady Chatterley's Lover, Villette, and A Room with a View. This one is not a classic, but is probably one of my favorite books (and I don't like romances) - Ha Jin's Waiting.