When I sit down to read fantasy, I usually judge it based on worldbuilding, magic, characters, and mayhem. Entirely subjective, of course, but I digress. The Fifth Season slays at three of those categories, and very nearly hits a home run with all of them.
Worldbuilding: This story reaches into several different genres at once, and manages to combine them flawlessly. It's an epic/dystopian/sci-fi/futuristic merge of everything I love in all of those genres. The world is simply staggering. Essentially, the land has been decimated, and Father Earth is rumbling and trying to cleanse itself of parasitic humanity, who has destroyed the world. Nothing new, of course, but the author adds in rich elements of magic to make it unique. Some people are born with part of their brain that is able to "sess" into the ground and sense the fault-lines in stone. They can use this to forestall earthquakes by smoothing them out, and keep the world from breaking apart. However, these individuals are too powerful to let loose, so a few nations try to keep them under control through various means (I won't go into too many details). All that say, the worldbuilding is engaging and hit all the right buttons for me.
Magic: As mentioned above, "sessing" is definitely different. Magic users who can use various elements of the world is nothing new to fantasy, but "sessing" is different than anything else I've read. For one thing, it's super specific. The wielder takes energy from whatever is around them and freezes it up, to use that energy to calm the earth and keep it from exploding. Talk about a giant disaster waiting to happen! I really liked this. Huge props to the author for taking something familiar and adding her own spin to it.
Characters: Here is where I docked off half a point (I know. I'm so mean). The characters were good, don't get me wrong, but I didn't connect with any one of them too closely. This story is a bit dark, and the characters are dark, too. Essun was the easiest to relate to - she's a woman, a mother, etc - but even she started to get on my nerves after awhile. Which brings me to one VERY interesting thing to note. The writing style is a bit jarring, and took some getting used to. It's written from both second person (she/her, him/his) AND second person (you, your) which is incredibly rare in fiction. Second person is hard to connect to, which is why many authors utilize it. But Jemisin dives straight in, and it took me aback. I got used to it, and it really helped to make this story unique. But I can't say I'm actually a fan of that writing style.
Mayhem: Wars. Battles. Arguments. Monsters. Generally wreaking havoc. That's my way of judging a plotline. This series is definitely headed somewhere fascinating, and I'm enjoying the chaos of the experience. However, it's chaos with a purpose, and the trail leads to what I love the best: hints at coming greatness/darkness/all the epicness.
So, you could say I'm a fan... crap. I just used second person.