With so many good anime, there's little time to waste time watching bad ones. However, there are numerous anime that are so terrible, and so messy, that you can't help but find a strange sense of satisfaction from watching. They may have a great scene or two, or else they're so terrible they somehow become entertaining.
The following anime are bad, to be certain, but nevertheless should take the time to watch them. Know that deliberately surreal comedies, like Ghost Stories, don't count. To be a bad anime, they have to fail at their intended goal; strange comedies that make you laugh do not qualify as failed anime.
Mad Bull 34
There are a number of anime that center on law enforcement, from Ghost in the Shell to Bleach. But the 1990 to 1992 anime series Mad Bull 34 is overtly a buddy-cop story in which police brutality and wanton destruction are a merit, not a problem. It's the action of 1980s action films like Lethal Weapon as seen through the lens of Japan.
Whereas normal buddy-cop films depict officers opening fire in crowded streets, Mad Bull 34 features a guy throwing grenades concealed between his legs, while pantless. It's a madcap anime that fans from the 1980s and '90s probably only saw as a Manga Entertainment commercial while booting up Ghost in the Shell.
Angel Cop
Another movie about cops who abuse their authority, the six-part OVA Angel Cop is a cyberpunk anime without much cyber or punk. It's just over-the-top violence. It also has one of the greatest anime dubs ever created. The plot is difficult to explain in a way that makes Angel Cop sound appealing (or anything more than generic), but the mayhem and terrible dub result in an essential work in the anime canon.
Ninja Slayer
A more modern anime, this time made by TRIGGER, 2015's Ninja Slayer is a bizarre pastiche of classic anime, as seen through the eyes of American weebs. The novels are "written" by Bradley Bond and Philip Ninj@ Morzez and translated into Japanese by Yu Honda and Leika Sugi. The only thing is that Bradley and Philip, supposedly American weebs writing a tribute to the anime they grew up with during the '80s and '90s, didn't really exist.
The anime relies on stereotypes you've seen a million times over. It's a repeat of a repeat, paying tribute to classic stories, boiled down to their cheesiest qualities. It's fairly ridiculous, which is its core appeal.
Chargeman Ken!
Chargeman Ken! is an absurd series of anime shorts from 1974. The concept should be simple: Ken is a superhero who fights shape-shifting aliens. However, there are few problems. The aliens are rarely shown to be violent, and instead, merely want to survive. Meanwhile, Ken's first instinct is to enact violence against all enemies.
Add to this awkward acting and almost motionless animation, and you have a surreal anime in which a kid murders aliens who barely resist. It's available on Retro Crush.
Genocyber
Genocyber is infamous among old-school fans. The 1994 OVA series centers on a brutal experiment in which two psychics are forcibly fused together to create an all-powerful weapon. The scientists attempt to create a monster with phenomenal psychic powers -- and they succeed. What results is an emotionally unstable weapon with the power to brutally depopulate countries.
Genocyber is ultra-violent, marked by depictions of sexual assault, torture and grotesque murder. It garnered a reputation for being one of the most mean-spirited OVAs of an era of anime filled with brutal violence. It is worth watching if you want to stare into the abyss of yesteryear. Otherwise, the sheer cruelty in this series will make it difficult to keep watching.