Roughing It is one of my favorite books, too, and passages from it (the old woman in the stagecoach) provided me with some great material for a college Oral Interpretation class presentation. (Maybe the professor was just grateful that it wasn't Poe's The Raven) I think Twain is funniest when he's on the road.

I'd be interested to hear how the rest of the Narnia Chronicles stack up on your most favorite to least favorite lineup. I remember always enjoying The Silver Chair, but for a journey-focused book, I liked The Horse and His Boy even better- maybe because it was an acquired taste, since it bored the socks off me the first couple of times I read it.