Akatsuki no Yona is easily one of, if not THE best Anime of its season for many reasons.
Interesting story, non-stereotype characters and well done character development, something that is becoming a greater and greater rarity. Not to mention that BEAUTIFUL original OP. A great enjoyment is also the detailed world the manga and anime has built. It just feels ripe for exploration and storytelling.
As is my preference I will speak a bit about the 3 main characters of the show, as I am more of a casual watcher and that makes more of an impression on me. (beware of spoilers from the manga up to chapter 69)
Let's start with Yona;... Best female character I've seen this season if I must be honest and I am aware I am stepping on a hell of a lot of toes here. her character development is believable and while some people might say it was too fast, I think otherwise it would have become too stale and annoying. I've come across many people who don't like how she is oblivious to Hak's feelings, but I think it is handled well enough right now. They just have to be careful not to push it into "unbelievable" territory.
Hak... Is my favorite character of the show hands down; Snarky and BADASS! Not to mention his devotion to his duty and by extent the former king is something to be admired. I also very much like the direction the manga is taking with his attraction to Yona as he was definitely not in love with Yona as she was before, but is slowly falling in love (and fighting it) with the capable, strong and independent woman that is growing in place of the sheltered and spoiled girl.
The last character I will talk about in detail is Soo-Won.... I don't think he is the evil prick most people accuse him of being. Every action he has done so far is more or less justifiable to an extent and he clearly has the kingdom's best interests at heart. Sure, he is an unscrupulous, has an ends-justify-the-means mentality and so on... And it fits. In the time period the show is taking place (relatively) he is THE PERFECT ruler. As to what animal would best symbolize him, many have said a snake, but I am not sure... I feel him more as a chameleon, as he is easily able to become whatever the situation calls for.
And that's unfortunately all we have time for here, as I am hitting the limit.