Feature and Follow Friday: What's the last book that gave you a "Book Hangover?"

Feature and Follow is a weekly meme hosted by Parajunkee and Alison Can Read. This is to promote blogs, have new followers and to be friends with everyone!!

RULES: (just tweaked them a bit but still the same idea!)

To join the fun and make new book blogger friends, just follow these simple rules:

1. (Required) Follow the hosts {Parajunkee and Alison Can Read} and Featured Bloggers.
2. Put your Blog name and URL in the Linky thing on either of the host's blogs.
3. Follow as many as you want.
4. If someone comments and says they are following you, be a dear and follow back. Spread the Love!
QUESTION: What is the last book that kept you up late into the night just to finish it?

A:  Altered (Altered, #1)
This book was nothing like I expected it to be and the ending was filled with twists and turns that had me looking at the book like this 0_0 I ended up not going to bed until 4:30am and unfortunately had to be up at 8:30 for work. Yes I had a book hangover, but it was soooooo worth it! 

What about you? What did you stay up late to finish?