Devilman: Yochou Sirene-hen

In both Devilman and Zetman, the protagonist can transform into a superhuman monster and are trying to keep their humanity intact. The main protagonist in both anime battles various monsters that can disguised themselves as humans that threatens humanity. Both are action-packed anime with lots of blood and gore. They also have a similar dark and gritty atmosphere. If you like one, you will enjoy the other.  

Both anime have a main protagonist who fights demons trying to destroy humanity. Both anime have similar demon designs (The bird demons in Makaryuudo Demon Hunter look very similar to Sirene from Devilman). Both are action-packed anime from a similar time period (late 1980's - early 1990's) with violence and blood. However Devilman is way more violent and has more nudity compare to Makaryuudo Demon Hunter. If you like one, you may enjoy the other.  

Both titles are action-packed anime that came out in a similar time period (late 1980's-early 1990's) with similar animation and atmosphere. In both anime, the main protagonist can transform into a powerful humanoid being and must use their new superhuman abilities to project humanity from monsters that can morph into humans. Both anime are quite action-packed, with a lot of violence, blood and gore. If you like one, you should enjoy the other. 

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 protagonist 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.  

Both anime have a dark and gritty atmosphere. They follow a main character who is half human and half demon, as he battles other demons that threaten humanity. Both anime contain a lot of action and gore.  

Same reasons than the first Devilman OVA. The voluptuous Sirene has inspired Mefist Dance and made a cameo. 

Both focus on a main protagonist who is merged with a monster, giving him supernatural abilities. The protagonist starts fighting against other monsters which threaten the Earth, but at the same time, must struggle to keep his humanity. 

Both of these anime fall under the same demographic and are intended for a similar audience. They feature a main protagonist who fights against supernatural creatures (vampires in JoJo, demons in Devilman). They also contain a lot of gore and violence. 

Both focus on a teenage boy protagonist that gets possessed by a demon (Amon in Devilman and Byoudo in Battle Royal High School) and uses his powers to fight off powerful evil demons. Both titles were released in a similar time period (late 1980's - early 1990's). Both are action-packed anime with lots of blood, gore, and gratuitous nudity. Devilman is more serious and has a horror vibe to it while Battle Royal High School is campier and over the top. If you like one, you should enjoy the other.  

Both anime involve the main protagonist that can transform into a powerful monster humanoid being that must fight against monsters that threatens humanity. The main protagonist both in Blassreiter and Devilman have to struggle to control their inner demon while trying to keep their humanity intact. They are also both action-packed anime with lots of blood and violence. If you like one, you will enjoy the other. 

These two titles were released around the same time (late 1980s - early 1990s). Wicked City and Devilman: The Demon Bird have a similar dark and gritty vibe. Both anime feature the main character facing shape-shifting demonic monsters that can disguise themselves as human beings in order to destroy humanity. Both are high-action anime with a lot of blood, gore, and gratuitous nudity. If you like one, you'll probably like the other.  

Both titles have the protagonist that can transform into a demon monstrous form and uses their power to fight for good instead of evil. The SoulTaker has a design that looks pretty similar to Devilman. They both feature supernatural elements with a dark and gritty atmosphere. Both anime contain a lot of action and blood. If you enjoyed Devilman or looking for another demonic theme superhero, I recommend trying out The SoulTaker. If you enjoy The SoulTaker, feel free to give the Devilman OVAs a try. 

Both titles are action-packed anime filled with violence, blood, gore and plenty of hellish demonic monsters. The main protagonist in both anime have to fight for survival and must give up some of their humanity to fight against powerful evil supernatural forces. However Devilman takes place in a modern day world while Berserk takes place in a medieval fantasy setting. If you like one, you will enjoy the other. 

Both titles were released around the same time period (late 1980's-early 1990's) and are based on manga from Go Nagai. Both Devilman and Violence Jack have a similar dark and gritty tone. As well as similar art, animation and a similar vibe. They are also both action-packed anime with lots of blood, gore and gratuitous nudity. Devilman and Violence Jack are also set in the same universe too. However you don't need to watch Devilman to watch Violence Jack. Violence Jack also contains graphic scenes of rape while Devilman doesn't. If you enjoy one, you should like the other as well.  

Both anime are based on manga from Go Nagai. They both have a similar dark and gritty tone, as well as similar character designs. Both anime feature the main protagonist fighting against evil powerful monsters. Both are action-packed anime with blood, gore and gratuitous nudity. If you like one, you will enjoy the other. 

Both titles were released in a similar time period (late 1980's - early 1990's). Both titles are action-packed anime filled with violence, blood, gore and plenty of hellish demonic monsters. As well as similar animation and a similar vibe. They both deal with the main protagonist (Akira Fudo/Devilman and Amano Jaku) fighting other demons that are trying to destroy humanity. However, Urotsukidouji contains graphic scenes of rape and sex while Devilman doesn't. If you like one, you should enjoy the other.  

Both are based on 1970's manga from Go Nagai. Devilman is greatly inspired by Demon Lord Dante and Devilman would not exist without it. They both have a similar dark and gritty tone with lots of blood, gore and gratuitous nudity. As well as similar art and a similar vibe. The main protagonist in both titles are thrown into a life of darkness and must save humanity from demons. If you like one, you should enjoy the other.  

Both are pretty much mindless Violence with yet strangely likeable main pyscho characters.