Debby, I loved War and Peace, too--but I only picked it up because we were in a non English speaking country and it was one of the ONLY things in the library I could read.
Mine would be Don Quixote. I read four chapters in a Spanish class and found it hilarious and approachable. Yet, despite owning a copy and having the new, special, illustrated YA version out from the library right now, I still haven't managed to read it.