Spoilers ahead so beware
I had heard of Attack On Titan many times before at various Cons and had never seen any reason to watch the Anime or read the Manga. I was recently able to watch it and boy did I enjoy it and soon after I started reading the Manga. If you like fast paced and character's that have actual development then you will love this. The premise of the world in AOT is that huge humanoid like creatures called the Titans, that resemble men, have come and seem to only have a stomach for human flesh. So the last of humanity comes together to build a series of three, 50 M walls I believe, in order to keep the Titans at bay. The story follows Eren Jeager and his friends as they go about their daily lives until a 60 M titan appears and destroys the wall and thus beginning pure chaos and horror. I have read that this manga has been compared to Game of Thrones for the amount of gore and death and it is an accurate description. This Manga is not for the faint at heart but you will laugh, scream in terror, cringe at happy go lucky monsters, and watch as an annoying little brat grows up into a man, I am dying for the next volume in the Manga.
I tried to not be too spoily