The Dervish House by Ian McDonald
I very much enjoyed this book, and I can see why it won a BSFA award. My husband has also read it, although he didn't enjoy it as much as me.
Set in near future Istanbul, it covers a week in the lives of six characters who live/work in an old dervish house on the European side of the city. In many ways the main character is Istanbul itself, various parts and periods of the city are explored in detail, at times it is almost poetical. I have never been to Istanbul and my knowledge of its history is limited to back when it was Constantinople, but the sense of the city and it's history are so strong that I felt I had some understanding of it - this is almost certainly an illusion, but creating powerful illusions is a mark of good fiction.
The main characters are: a old Greek academic who is part of a shrinking community; a secluded 9 year old boy with a heart condition who fancies himself a detective; a religious art dealer from an aristocratic family and her ambitious stock-trader husband; a determined young woman from rural Turkey who wants to prove her worth to her large family by marketing her cousin's revolutionary nanotech company; a troubled man who is being cared for by his religious brother.
The SF elements are mostly nanotechnology and advances in robotics. These allow for swarms of tiny robotic components that can reassemble into a variety of shapes for different uses. Nanotechnology lets people increase the performance of their brains and bodies, and one of the plotlines is about visionary technology that could see humanity altered entirely. There is also a strong vein of history in the book too, which is probably one of the reasons I enjoyed it. There is the recent (from our viewpoint, future) history of Turkey joining the EU. There are bittersweet memories of the 80s, when young love existed against political upheaval. There is the legacy of the Ottoman Empire, its decline and Turkey's liberation. There is plenty of Islamic history and mythology as one character searches for a lost artifact and another has mystical creatures enter their life - this sense of the fantastic is probably another reason I enjoyed the book so much, I do like a bit of Science Fantasy.
An Abundance of Katherines by John Green
This is the third John Green book I've read and it's probably the most amusing. It's about a boy called Colin who has dated and been dumped by 19 girls called Katherine, at first it was a coincidence, then it became a very specific preference (apparently the way I spell the name would not be acceptable). Having been recently dumped by Katherine XIX Colin is taken on a trip by his best friend Hassan and they end up in Gutshot, Tennessee, helping with a local history project. While all this is going on child prodigy Colin (who is afraid that despite his potential hell never be classed a genius) is attempting to come up with a mathematical theorem to explain relationships and predict who will dump who and when.
The book has many things which seem to be John Green staples: a young male protagonist who is confused about his future; a part of the USA that you don't tend to see on TV; a larger-than-life, foul-mouthed best friend; and a lot of random facts that are part of the main character's quirks.
Despite having familiar elements the story was in no way predictable, I honestly wasn't sure how it would finish -especially as previous John Green books I've read have had darker themes than this one. One thing I enjoyed about the book was the footnotes (I read a lot of Pratchett as a teenager, so this is probably unsurprising, plus I can be a rather tangential person myself), which contained both facts that Colin knows and interesting narrative info. A major theme of the book was Colin realising that, despite his impressive brainpower and brilliant academic skills, most of his potential was not necessarily going to be of any help outside of education. This seems like a good message for young people (even those who aren't prodigies).