There are two reasons I love The Martian. First and foremost, it's a great story. Fresh, original, somehow weaving dense science into a compelling, readable narrative. Second, it's something of a miracle that any of us have read it. If you're not familiar with the story of how Andy Weir's novel came into being, check it out. Put briefly, he did it on his own, and the publishers and moviemakers came calling. It is a Cinderella tale to writers, and I both salute and envy him.
Back to the first point. A large part of why The Martian works is because Mark Watney is likable, accessible, funny, and deeply human. His quirky irreverence melds with serious brain power to keep him alive under circumstances where most of us would curl up and cry ourselves to death. He's Robinson Crusoe meets MacGyver meets Peter Venkman, and it works. Every page I read (and I consumed it in a single transcontinental flight) made me jealous he wasn't mine. And that's the highest praise I can render.
The book is a triumph, and, in a rarity these days, so is the film. Matt Damon is as good as we've seen him in a long time with a performance that bears little resemblance to his pathetic effort in Interstellar. If you haven't read or seen either, I recommend both (book first, of course). You might never eat potatoes again.