Free at the time of posting for Audible members, series 1-8 "Fry's English Delight" by Stephen Fry.
Also, I was asked to merge my US account with my Australian account by signing up for, yet another, discounted subscription period. (First 3 months for AU$8.) Strangely, it wasn't mentioned before the actual transaction took place that the subscription was discounted. Might be worthwhile considering whilst your at it.
So with your merged account, do you still have access to all books in the American store? (I believe that the aus store has alot less books).