The Secret History, Donna Tartt. Another thrift store find. (The previous one was good all the way through; it only flagged briefly once. Beautiful writing - No Great Mischief, Macleod.)
This is on my to-read list! It popped up on Buzz Feed's list of 65 Books You Need to Read in Your 20s.
I just started Vampires in the Lemon Grove by Karen Russell and Why We Broke Up by Daniel Handler (aka Lemony Snicket). Both of them keep startling me because they're so unlike anything else I've read.