Well? Have you read The Martian yet?
If not, and you're still on the fence, there's a very nice interview with author Andy Weir over on the Nautilus site: The Hit Book That Came From Mars.
It's a great interview: Weir is very relaxed and revealing about how The Martian's success surprised him as much as anyone:
You know, I spend a lot of time trying to figure out why people like the book, because I’d like to write another book that they like that much.
It's a great book; he's a great writer; he sounds like a good human being, too.
I hope all this attention encourages him to continue writing great books.