So, what is this about? Content? Artwork? Anything?
My vote would be the Star Trek: Deep Space Nine plastic spines. One of mine has already split, even though it was only used long enough to transfer to an Alpha case.
Next, along the same idea, Babylon 5. The paperboard spine gets a wicked crease unless you never open it.
He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. -- Unknown