One of the things that I loved the most was Elisa being fat. I've never really read a book where the heroine was this fat, it was sad and hilarious. It also brought a different appealing aspect to Elisa, as most heroines are skinny and pretty, or just slightly on the chubby side, and Elisa really didn't care that much, as she just loved to eat. It was great that she didn't really care about her figure, but it was also brilliant to have her lose all that weight as the book progressed, I could see very clearly Alejandro's face when he saw the new Elisa.
When the book took a turn and Elisa was kidnapped, that's when my interest was really captured. The way that Rae Carson wrote the journey was great, although hardly any of it was written, you could still feel it's power. Elisa changes so much on the journey, she basically becomes an entirely different character, which never works well in most books, but this one, it worked brilliantly.
What I thought was really sad/great was Humberto. You could see even from when they first meet, that Humberto had a crush on Elisa, even though she was really fat. SPOILER!! It's really terrible how he just dies, and Elisa has no time to mourn him. He was such a perfect character, he never pushed Elisa, and never discarded the fact that she was already married. I was heartbroken when he died, I can only wish that he becomes alive somehow in the future (which I know will never happen).
The Girl of Fire and Thorns was a wicked awesome book, and had such a perfect plot, characters and even the writing style can be described as amazing. I recommend this to every young adult, just give it a try, it will blow you away.