Started in March and finished book 14 nine months later. The books started slow but got better and better, terminating in a phenomenal finale. This is an epic high-fantasy series with an elaborate "magic" system and all kinds of other interesting features and worlds.
Also, what makes it even more special: The first 11 books were written by Robert Jordan, who unfortunately passed away and tasked Brandon Sanderson with the ending of the series using his notes. Incredible how it worked out.
EDIT: From what I read here, a lot of people are stuck around books 6/7/8. Yes it's a drag, but it will get better and in the end it will be worth it! Some people recommended the audiobooks if you really have trouble to get through.
EDIT: Guys, thank you so much for all those awards!! I never expected this to blow up like this!