<i>The Pearl</i> absolutely ruined Steinbeck for me. I think that was the first book I really and fully hated. And it didn't help that I wasn't a huge fan of the film of <i>The Grapes of Wrath</i> I watched.

However, I did enjoy reading <i>Of Mice and Men</i> (though it resulted in the second worst mock trial I've ever participated in).

I've also heard some good stuff about his King Arthur book. He seems pretty love it/hate it for most of his books.