Have you HEARD about the Throne of Glass book series by Sarah J. Maas?
When I first started reading it, I was skeptical: how can one book about an assassin competing with other assassins be so long? Why are there so many books? Why are they so popular?
...and then I tried reading one. And then the second. And the third. I'm currently on the fourth book (Queen of Shadows). There are set to be seven books in the series, not counting the prequels.
The series starts out with a simple enough premise: Celaena is an expert assassin who is freed from a harsh desert prison in order to be trained as the prince's champion in an Hunger Games-style competition that could win her her freedom. Then, suddenly, what seems simple becomes complex: someone is sabotaging the competition. Meanwhile, Celaena is falling in love, the kingdom is in turmoil, and suddenly a rebellion is afoot.
Celaena is a really likeable (and imperfect) heroine, in addition to being a total badass. The world starts out fairly small, and opens up with each book until suddenly you get witches and wyverns and fae in ADDITION to excellent battle scenes and kingdom intrigue.
If you liked the Hunger Games series or the Red Queen series or Game of Thrones, Throne of Glass will be the perfect series for you! Don't let the size of the books scare you: even though they're big, they're a fast and fun read.