Tokyo Ghoul is an amazingly well told story. In a twisted world where ghouls ( humanoid human flesh eating creature) live amongst the human, Kaneki find his life turned upside down by a cetain incident that turned him from human to ghoul. The author successsfully depict the anxiety, fear, and despair that Kaneki experience as he struggled to stay human despite of his changed state. And as he learn about the life of ghouls, he is eventually dragged to the elongated fights of ghouls against their own kind and the doves, humans who fights ghouls.
Tokyo Ghoul started slow as Kaneki learn his way to live as ghoul but the pace will fasten as the fights began. In the anime you will learn little about ghouls and their abilities so reading the manga won't be a waste of time.
To me , this series is great because of its natural flow.
The author successfully depicts Kaneki's struggles wih his new life as ghoul:how he struggle to restrain his ghoulself, how he wish to protect his ghoul companions, how he finally accept his ghoul part and strive to get stronger to protect his companions. Through the story we feel like we want to cheer for him and pity him for everythong that happen to him. Other chars are also well developed, ghouls and dove alike. They make you feel you want to cheer for both sides as you have favs on both sides.
The balance of power between ccg and ghouls are great, while humans have disadvantge in term of raw strength it's well covered by increasingly better equipments and strategy. Both investigators and ghouls have badass figures, one that won't fall easily even against stronger adversary. Also, kaneki despite of his constant growth was never overpowered. Part of this is maybe because he stil fear he power that will make him lost himself.
Also Tokyo Ghoul has seemingly deep plot involving secret orgs and a (mad) scientist who is obssessed in turning human to ghouls. The ccg is also not free of controversy, and there seems to be bigger mistery to the world as why ghoul could exist and why they have very similar appearance to human.
Overall this series is great. Don't worry about the ending, it doesn't seems to be the ending of the series to me, although I did somehow discouraged about it for some reasons. Don't get me wrong. Even at it's end I found myself still hungry for more chapters of TG and the story has definitely ways to go on. Those who said its bad are like people who stopped watching a series after its first season and said it has bad ending.
The sequel has begun its serialization so for you who was put down by the ending or after learnt the ending, cheer up. It may start slow but it will definitely get better. This series is great and it has potentials to be even greater.