The Girl on the Train. But, is it as good as so many have said? Short answer: yeah, pretty much.
This is one of those books that my former High School English teachers would have referred to as "airport trash." Don't despair, they were snobs with literature. Yes, the book has few redeeming qualities. Yes, you won't read it and think to yourself about the beauty of the prose. Sure, the characters are fairly unrealistic and little time is spent rounding them out. But, boy oh boy, this is one fun book to read. It's truly a page turner; nearly impossible to put down. My wife read in 3 days, while I took 4. Sure, it might be "airport trash" but this book blog always basis the rating on one main criteria: is it entertaining? The Girl on the Train certainly is.
Basic premise: there's the girl... on a train. Oh, you want more? Well, she's kind of nutsy and she starts seeing some things while on the train and starts getting involved with some people, and she likes to drink and not remember much. That's about all you need to get going, really.
The book is quite a fun read. Hawkins does a great job of getting you into it early and it's pretty easy to see why it's been so enjoyed by many people. It's a simple and fast read. The plot is easy to follow. It's chock full of exciting and juicy dialogue. Of course, it has some drawbacks. As mentioned earlier, this book pulls no punches about what it's going for. It's not going to be anything more than a quick and easy read that keeps you entertained and constantly guessing. There is no existential question or any real deep thought in it at all. But, again, as long as you know what you are signing up for, it's a good ride.
The comparison between it and Gone Girl (my review of it here) are obvious and apt. Both books follow similar arcs and have similar female protagonists. Both books keep making you think something else might be happening and you're never quite sure what's going to transpire next. Both books are wildly entertaining. For my money, Gone Girl is better. It's a smarter novel and there's more depth to the story and characters. The Girl on the Train is a really good knock off but not quite the real McCoy.
Not sure if you are looking for much more but, at this point, go pick it up if you have not read yet. Again, it's quick, fun, and you won't regret the time not spent on something that would really be more illuminating; you'll be enjoying this one too much to think about that :)