The Martian is about a guy stranded on Mars, trying to survive on his own until he can be rescued. Really compelling, but most of all perfect as an audio book. Mark Watney talks to you directly about his daily troubles, which makes it feel less like you're creepily reading someones diary and more like a friend telling about his adventures. The voice acting is just so well done and gives the characters more depth than printed words could. I read it as homework for the Hello Internet podcast, but they complained about the dad jokes and the amount of numbers. I had no complaints about that at all because in audio form both seem to fit Mark's character. He has to keep up his own morale so he tells stupid jokes and he babbles on about all the calculations he makes to confirm to himself that he's smart and capable. I really felt for him, from beginning to end.
For some more books in the 'outer space' category: both Ender's game and the Robot series by Asimov largely take place away from earth. Ender's Game is about a boy who gets recruited to be trained as a commander to fight an alien species. It's a pretty depressing story about loneliness and losing friends at times, but it's also about finding the strength to do what is right. It gives a lot of insight into Ender's mind. The female narrator in the audio book makes his sister Valentine sound like an melodramatic bimbo though, so I suggest you read this in print.
The Robot series was just really really good and I will recommend it to anyone who's even just vaguely interested in science fiction. They read as detective novels, but with the added bonus of robots and societal issues concerning them. I've been a huge fan of Asimov since I've read I, Robot and The Gods Themselves and though the setting of this series is very different the writing style and humor are excellent as ever. The audio was really good as well. Elijah with his gruffness and Daneel with his ever polite voice found their way to my heart.
Now for something completely different: Watership Down. I would've thought a book about the epic journey of talking rabbits would have crossed my radar sooner but I only heard about it last year. I bought the Oneworld Classics illustrated hardcover edition and I have no regrets spending the extra money. It is so beautiful that even the guy who sold it to me at the bookstore was slightly in awe. You could just buy it for the pretty pictures but I do recommend actually reading it. It starts of a bit gruesome, but it gets better and happier. And the best thing: rabbit mythology. The rabbits tell each other stories about their god Frith (literally 'the sun' in Lapine) and the trickster El-ahrairah. Those were my favorite bits.
If you're really into non-human characters you should try Flatland. It's about a square called A. Square who lives in two dimensions (Flatland), but also journeys to worlds with three, one and even zero dimensions. It's really interesting and written quite well, especially considering it was published in 1884! I'm just going to paste in the review I wrote about it nearly one year ago, because I still feel the same about it.
The only thing dated about this book is the writing style, but even that is not a bad thing once you get used to it. I love how it invites you to perform thought experiments without being preachy or overly educational. I usually read it late a night, taking breaks from reading to take a moment and imagine what four dimensions would look like.
I'm not sure how I'm supposed to feel about the portrayal of women in Flatland. It is unclear to me whether it is meant as criticism on the status of women in Victorian times, or that it is a representation of the authors own ideas. He is more obviously critical of hierarchical structures (which I like), so maybe I'm just too sensitive to demeaning portrayals of women.
All in all, I think it's a great read, which invites the reader to review the limited perspectives we have as three-dimensional beings.
And last but not least, a Dutch book called Het zijn net mensen or in English: People like us by Joris Luyendijk. I met the author once at a lecture and his speaking style as well as his writing style are really enjoyable. He seems like a really open and honest person, with a bit of satiric humor to show that he's not fooled. This book is about his time as a news correspondent in the Middle East. He writes about the horrors he sees and hears about, but mostly about the way the media portrays these things and the influence this has on public opinion. It is not a gruesome book though. Luyendijks writing tone is optimistically idealistic, which leaves you with a positive view for the future of the media. Not so much for dictatorships. Those are pretty bad.
So yeah, that's my kind-of-diverse SF-heavy favourite-books-of-2015 list. If you've read any of these as well, leave a comment and let me know what you thought of them. Or even better, tell me I've convinced you to read some of these!