Most of the replies I've seen so far seem to focus on works which are long, or which deal with large themes. I think "War and Peace" for instance, while it might be long, wouldn't necessarily be bad (so long as you skip all that philosophising at the end - well, I did). After all, Wagner is long, and deals with large themes, but people sit through it. (yes, I know...opera, not ballet)
I see something by Ionescu as perhaps the kind of thing to aim for - "Chairs", maybe.
Of course, I am well-known for my ability to predict the success of musical theatre productions. I recall driving home from work and hearing Andrew Lloydd-Weber interviewed about a new musical he was hoping to make based on T. S. Eliot's cat poems. No way! I said.
Then, a few years later, I was living in The Barbican (apartment development in the City of London) We were offered discounted tickets for a production of the new musical version of "Les Miserables", when it opened at the Barbican Theatre. Not worth baby-sitting money, I thought. Ah well.
Fran