I am currently reading my way through a long list of science fiction and fantasy titles. (http://www.npr.org/2011/08/07/138938145/science-fiction-and-fantasy-finalists if you are interested in the list).
I read this as a comic (good old Classics Illustrated) when I was a kid. Thought it was time that I tackled the real thing as an adult--I was surprised at how old it is! And fairly readable despite its age. I guess that's what makes a classic.