The Sea Wolf by Jack London has a tremendously imposing yet tragic antagonist character pitted against the weakling main character, taking place on a ship. It features some of the usual ocean going ventures of violence and mutiny, weather and shipwrecks, but with looks at morality, value of life (or lack thereof), and conditioning and adaptation among others, that are all illustrated as eloquently as London does. Likely every library has this one.

And since Sci-fi was brought up, no list, however brief, is complete without some Arthur C. Clarke. There's a huge amount in his bibliography; well over 50 years worth and still counting. He imagines well with grand scales and themes yet focuses on the well developed individual characters and plot. Again, common in libraries.

And for most casual reading, I've dug into quite a few Louis L'Amour. Usually short novels good for the historic settings, action, and overall style spanning centuries of uniquely American history. I'd agree his title fits...America's Storyteller.