The Martian by Andy Weir (Kindle version is $3)
This book has had a lot of buzz around it because the guy who wrote it basically just had the story on his website, but the more and more people read it, the more and more people wanted it in a "book" form so he put it on Amazon for the lowest price and it took off from there. To the best seller list and now a movie (currently filming). It's about astronaut Mark Watney, part of a crew sent to Mars for a mission, but in a turn of events he was left stranded all alone on the planet. Mark is lovable from the first line, he's a GREAT character, absolutely love him. It's a book that follows his efforts to get back to Earth, which are harrowing and seemingly impossible yet his trials and tribulations will not let you put the book down. Can you tell this is Mr. Weir's first book? Yes. Does that hinder the story? No. He has jammed so much research and science into this book you forget that it's just a novel. He did such a great job. It's the story of a dude with a great sense of humor and joie de vivre that just happens to take place on Mars. I highly recommend this book! It's one of the best stories I've read in a long time!
Footnote: The movie is being directed by Ridley Scott and Mark is being played by Matt Damon. I can't say I'm happy about either choice. I'm nervous Scott is going to make it more about Mars than Mark and more deadly serious than optimistic. I hope I'm wrong.