If you're looking for similar to Fate/stay night, you might like these titles. All recommendations are made by Anime-Planet users like you!
Tenchi Universe is a twisted continuation of the original Tenchi series. Through a different set of circumstances, Tenchi Masaki meets up with characters such as Space Pirates and Galactic Princesses. Tenchi is then taken on an emotional roller coaster ride, as well as a space epic, as he discovers new things about his new friends, himself, and his destiny.
On the eve of nobleman Oz Bezarius's fifteenth birthday, he and his loved ones gather to celebrate in a coming-of-age ceremony. But after Oz steps under a long-stopped clock and the hands finally move once more - thus fulfilling a mysterious prophecy - he is violently thrown into the legendary prison known as the Abyss by three cloaked intruders. Existing in another dimension, the Abyss is home to lifeforms born within its walls known as Chains; these beings can only live in the real world if they make contracts with humans, binding their power to the person's body. However, there's a catch - in time, the human will be overcome by the Chain's power and then thrown into the deepest level of the Abyss. When Oz wakes up in the Abyss he is quickly attacked by hungry Chains, only to be saved by one named Alice - a Chain who appeared just before he was thrown into the prison. Together, the two make a contract and return to the real world, where they are enlisted into the Pandora organization - a group researching both the Abyss and the trio that threw Oz into it. Along with members of Pandora, the duo searches to find Alice's lost memory fragments that are scattered throughout the world, to discover the secrets of the Abyss, and to determine if there's a way their contract can be broken without killing either Oz or Alice.
PH and F/SN definitely top some of the more similar anime I've seen in a long time. Usually I have trouble thinking of recommendations, but not for thse two. For one, they both involve a male protagonist who... is "coming of age" and through a series of events, ends up having a very strong female lead protecting them. And what I like best is that, they clearly establish that Saber/Alice both dominant the world they're in (and they don't just fall over when their opponents come at them). They focus more on Oz than Shirou (I think) in terms of character development but they both pretty much grow on you.
In terms of plot though, they both involve some sort of "save the world" theme, although I think PH is more about revealing the past while F/SN is more about saving the future. PH definitely has a stronger mystery feel and (despite the poor animation) the ending isn't the most conclusive. On the other hand F/SN is based off a game, so it definitely has a conclusion and romance to boot!
Ritsuka has nowhere to run or hide. He lost his memories and his mother’s loving support, and then his brother -- his sole defender -- was brutally murdered. He is entirely alone until Soubi appears, saying the words he most wants to hear, but refuses to believe: “I love you and will do anything for you.” Flung into a world of intrigue and magic, where bonded pairs battle and only Soubi can fight for him, he struggles to find his brother’s killer. Yet he must also face the most bitter question of all: if you can't remember who you were, does that mean you don't know who you are?
In both shows, an unsuspecting boy is thrown into a bizarre world of fighting due to the lifestyle of a dead relative. Both of these shows involve groups of fighting pairs who have a master/servant relationship, with the fighter exerting the effort while being subserviant to a master who can aid in battle by increasing the fighter's strength and giving orders. In both cases, the pair is bound together by some deep destiny and their bond allows them to connect with each other on a more spiritual level. The fighting is similar too, involving magic and complicated relationships with people who are supposed to be enemies. The two shows are dark and bittersweet and overall have many similarities.
In a futuristic world almost barren of life, mankind is confined to mechanized domed cities where A.I.’s control all aspects of life. In this world, humans are no longer born, they are manufactured in a production line; and alongside them live androids known as autoreivs. Within one of these domed sanctuaries named Romdeau lives Re-l Mayer, one of a few citizens who aren’t entirely prevented from thinking. Her grandfather's prominent position and the affection of the scientist Daedalus have left her more free will than is normally allowed, but Re-l has started to question the sanctity of the city and the citizens' perfect way of life. With mysterious beings known as proxies causing havoc and a man named Vincent causing great influence on her life, Re-l must travel outside of the city to find the answers she seeks and discover the mystery behind "the awakening".
If you liked ergo proxy or vise versa fate/stay night then heres why you should watch the other: ergo proxy has a main character with a dark past and the same with fate/stay night, they both include super powers and highly intense action scenes, and their stories are similar.
Long ago there was a battle between angels and humans, which ultimately ended with the angels’ retreat. Twelve thousand years later, the angels have become active again and have begun harvesting humans for nefarious purposes; and only the pilots of the ancient mecha known as Aquarion are able to oppose the angels' tools of war. The pilots have special powers, but the secret to defeating the Angels once and for all lies with the reincarnations of the two beings who defended humanity against the Angels in the past: Apollonius, an Angel who turned his back on his kind in order to protect humanity; and Siren, his human lover. Only Apollonius can awaken the true strength within Aquarion that is needed to defeat the angels; but who is the reincarnation of Apollonius?