Honestly, there's way too many that I think everyone who loves books should have read at least once in their life.
Some books that I had to read I ended up being entertained by, one of them being Mark Twain's Huckleberry Finn, and both 1984 and Animal Farm by George Orwell I feel are also entertaining.
Depends on the context of the class, really. Some books would be entirely irrelevant to the class.