One of the most difficult, but most rewarding reads is a book written in dialect. Difficult, because dialect usually adds spelling to the writing which is consistent with the sound of the dialect, and has NOTHING to do with proper spelling. Most rewarding, because 'getting' the dialect lends a richer experience to the read.
One of my favorite books in dialect is "The Adventures of Huckleberry Finn", the presence of certain insensitive words notwithstanding. I read this book aloud to my sons as they were growing up, and being the person I am, I read it 'in character' - a different voice for each character, and, to the extent I was able, in a close approximation of the accent described in the book. Doing that gave me an opportunity to talk to my boys about race, and culture, and how certain words weren't proper to use in regards to others who might look or think differently than they might. Reading "Jim" properly gives one a feel for him and a sympathy for him as a man. That, I felt, is the most valuable thing my sons got from having "Huck Finn" read to them.
Now, there are two new candidates for inclusion in my library of books I've read, both of which are 'dialect' books.
"A Confederacy of Dunces" by John Kennedy Toole - a giggling comedy set in a New Orleans beset by a cast of characters that will make you laugh just thinking about what they've done.
"The Help" by Kathryn Stockett - the 'dream book' we all want to write. This is her FIRST novel, it's a best seller, and it's been made into a movie. One suspects the book might be good. In dialect or otherwise.