If you're looking for anime similar to Ergo Proxy, you might like these titles. All recommendations are made by Anime-Planet users like you!
Naota Nanbada is a boring young boy who leads a boring life in a boring town. His older brother has left for America, and the closest he comes to any excitement is when his deadbeat dad has too much sake. But things change one day when a bizarre girl zooms up to him on a scooter and smacks him in the face with her guitar. What's more, once Naoto returns home he discovers that this strange woman has arrived ahead of him and moved in! Not only does she constantly engage in perverted activities with Naota's father and flirt with the young man himself, but she also claims to be an alien who is searching for the ‘Pirate King.' Now, Naota must learn to live with this new intruder, deal with an odd government agent who sports exceptionally large eyebrows and the mysterious Medical Mechanica, and come to terms with the fact that there are a variety of robots and weapons emerging out of his head - amongst other things. Perhaps boring wasn't so bad after all...
In the near future, demons with the ability to fuse with machinery and infest corpses have begun terrorizing mankind. Dubbed 'Amalgams', no one knows how they are created, or where their abilities originate from. As the random outbreaks continue, the general population begins to panic, demanding protection from these vicious beasts; enter XAT, a military unit created solely to counter the Amalgam threat. Despite being a highly skilled unit, however, they find themselves hard pressed to contain the threat, let alone subdue it. To compound matters further, a new type of Amalgam surfaces that proves even more devious than the rest - one made from the human, not machine. Yet all is not lost, two of these new Amalgams - the feisty Gerd and the mysterious Blue - actively oppose the others. With the odds stacked against them, will they be able to protect mankind while simultaneously being shunned by it?
Ergo Proxy and Blassreiter involve human characters that also have a powerful alter ego inside them. Throughout the series, said characters struggle to control their inner demon, wrestling with their own humanity. If you enjoyed that plot in one, I think you will enjoy the other.
In a world where corporations snuff out the competition by sending fighter jets to attack their offices, teenage pilot Kannami Yuichi is reassigned to a new base. There, he meets Tokino, a carefree pilot who enjoys the company of older women, and Kasanagi Suito, his superior officer who he slowly falls for. However, not everything is as it seems. Soon, distressing questions are raised about Kannami's predecessor, a race of perpetual adolescents known as the Kildren, and the enemy ace of the skies, Teacher.
Well, both of these anime(s?) deal with the human condition as a whole, and the existential crisis in particular.
In both anime(s?, again), the main view point is that the ad hoc raison d'erte of the average human is determined by the role he is given in society by "the powers that be".
In Ergo Proxy, we see manifestations of those powers in the Regent and the Council, and, ultimately, Proxy One. Proxy One is also a hint to the idea of Free Will, but to save the spoilers, I won't ellaborate on that.
In Sky Crawlers, these powers are mainly the government.
The main difference between the stand points of the two anime(s? once more) is that while Sky Crawlers maintains that the human condition is a closed circle of events, and existence itself will keep it's balance by replacing rogue peons should they try and break free, Ergo Proxy claims that each individual has the power to challenge the status quo of the world.
In the future, androids live side by side with humans – but not as their equals, as their slaves. Though they look identical, these androids must display a holographic ring over their heads so the difference is clear. One day, a boy named Rikuo finds abnormal activity patterns in the logs of his own android, and alongside his friend Masaki, he sets forth to find where the android has been. Much to their surprise, the duo discovers a secret café known as Eve no Jikan with a single rule: within its walls, there must be no discrimination between humans and robots. In this place, androids appear to be human and are even displaying signs of independence – a trait that should not be possible. Rikou finds his perceptions increasingly challenged as he struggles to come to terms with his own android, and the relationship between man and machines...
Rokuro Okajima is a small-time salaryman who is carrying documents for his company, when the ship he's traveling on is attacked by pirates. Kidnapped, he discovers to his dismay that his employers' main concern is to ensure the documents don't get into the wrong hands, even if it means sending the carrier to the bottom of the sea. Now, with his former life ruined and his kidnappers seeming comparatively friendly, "Rock" decides to join their merry band of mercenaries, and sets out with a new career to the shadier corners of the South China Sea.