Tokyo Ghoul, Devilman: Crybaby Recommendations
Both are horror anime with a similar dark and gritty tone. Both protagonists are a living normal life before they turn into a monster. Both protagonists are struggling to keep their humanity intact while battling against evil supernatural monsters trying to destroy humanity. Both are action-packed anime with lots of blood and gore. If you like one, you will enjoy the other.
Premises are very similar. Main character gets fused with evil/dark being, gains its' powers, and has internal struggles from trying to cope with being both human and a demon/ghoul. Both are dark, gritty, and violent.
Devilman Crybaby more heavily emphasizes sexuality as a theme than Tokyo Ghoul.
If you enjoy one, you'll probably enjoy the other.
Kaneki (Tokyo Ghoul) and Akira (Devilman) are very similar characters in that they both start off as weaklings at the beginning of their respective stories. Its not until after they gain their monstrous powers that they change into stoic, aggressive badasses who fight against other monsters in an urban environment. They also both deal with the inner conflict of balancing their humanity with their new monstrous nature (be it ghoul or devil). Other similar elements between these two series are body-horror and gore, so if you like either series chances are you'll appreciate the other.
devilman de go nagai, inspired to many titles example to tokyo ghul, a boy who lives between one race and the other. but I prefer devilman, and this is the version most attached to manga
These two anime both involve a young male that starts off normal and later becomes a monster. In both anime, they must fight monsters that are a danger to humanity while not becoming a total monster at the same time. These two anime are also filled with extreme violence, blood and gore too.