The Bible, Homer's Iliad, and Shakespeare's works are some of the most important ones in Western culture. I wouldn't say they're unapproachable at all. They may be more difficult to read than a modern teen fiction novel, but they contain archetypes and language patterns that were foundational for works that came afterward.
Thinking about it now, Beowulf should be added to this list. That's another great way to teach students about the evolution of the English language.
Thinking about it now, Beowulf should be added to this list. That's another great way to teach students about the evolution of the English language.