The plot is about Japanese teen Yamato Hibino, who is sucked through a time warp into the past, where the dinosaur army of the Dragonia Empire threatens the world, and Queen Aira of Mu needs Yamato to help her fight back with the aid of the stone-made guardian God Mazinger, which looks suspiciously like a giant robot.

Slight retelling of the 2001-2002 Mazinkaiser OVA series.

Masaki Kenshi was taken from his home and was sent with a combat suit to assassinate the young queen Rashara. His mission was unsuccessful and he was captured and would have been typically executed for such a crime. However, Rashara, seeing that Kenshi was forced to carry out such a mission, pardons his life. She allows him to stay at the pilot academy and he becomes friends with many of the women surrounding Rashara. However, there are deep secrets that may threaten the comfortable life that Kenshi is living right now.

Based on the hit model kit line by Kotobukiya, Frame Arms Girl. This manga follows Gourai, a newly activated Frame Arms Girl at Factory Advance as a test for self aware AI along side several other FA Girls.

Stand Alone Complex takes place in the year 2030, in the fictional Japanese city of New Port. The story follows the members of Public Security Section 9, a special-operations task-force made up of former military officers and police detectives. The manga presents individual cases that Section 9 investigates, along with an ongoing, more serious investigation into the serial killer and hacker known only as “The Laughing Man.”

Updating

.......

The genius robotics professor, Dr. Komyoji has created Jiro (who has the ability to transform into Kikaider) – a humanoid robot tasked with the protection of Dr. Komyoji’s son, Masaru, and daughter, Mitsuko. Gifted with a conscience circuit, which has the power to simulate real emotions that helps to distinguish between “right and wrong”, Jiro must protect Mitsuko and Masaru from the evil Dr. Gil who wants Jiro to join his army and aid in his goal of world domination.

Energy crisis, scarcity of resources, etc. Leads to its only logical conclusion: war between east and west.

Updating

An evil dinosaur-wizard-alien named Goa plans to take over earth and get rid of all the humans living on it. Earth, the creator of earth, makes three "Rocketonians" to stop him: the golden giant Magma, his mostly absent throughout the whole series wife Mol, and their son Gamu, who is made in the image of the main character, Mamoru (a human boy).

From Viz: The official comic adaptation of Bandai's Cartoon Network hit, a stylish "manga meets film noir" story which goes BEYOND the plot of the TV series! Paradigm City is the city of amnesia--40 years ago, SOMETHING happened that wiped out the memories of the residents, forcing them to recreate their culture from scattered fragments. In this world only 40 years old, Roger Smith is a negotiator--a go-between for police, citizens and criminals in high-risk diplomatic situations. But something else survives from the forgotten past. They are the MegaDeuses--giant robots created by the city's former inhabitants, or perhaps by the forgetful citizens themselves. When crime and madness strike, Roger Smith brings the guilty to justice with the giant robot called THE BIG O.

From Fate: Kyouhei, after moving away to Tokyo from his old town to get away from the events that happened, is on a goukon with his friends, including his old neighbor, Shiba. After drinking for a whole night, he and Shiba discover a dead, bloody, body in the elevator. He is told by his younger sister, Utao with her Kamisama Doll, that Aki, an old friend, and his Doll, are the culprits responsible.

In the year 2031 A.D., Earth has become ravaged by the attack of insect-like aliens called the “Blue”. In an effort to escape their destruction, humanity abandons the planet and now resides in an orbiting space station called “Second Earth”. After being diagnosed with an unknown disease, Kaido Yuji was put to cryogenic sleep on Earth until a cure was found. But he’s given the rudest awakening of his life when Armour Shrike pilot Marlene Angel comes to pick him up, and Yuji witnesses in horror as her unit is wiped out by the Blue. Now Yuji must survive against the harsh new rules of this apocalyptic world -- and find out the true nature of his strange disease.

Tatsumiyajima is the central island in the middle of a small cluster of islands, in a sleepy backwater of the Japanese isles. Not much happens there, and the island's young people go to school knowing that their lives are likely to remain peaceful and undisturbed. Or so they have been taught... but the truth is different. The fate of mankind is on the line, and Tatsumiyajima is the last line of defense against a hostile and incomprehensible enemy. At the center of it all, fighting for Humanity's continued existence, is the giant robot Fafner, the dragon that guards this final treasure of mankind. (Source: Crunchyroll)*Note: The original TV anime aired back in 2004. A second season titled "Soukyuu no Fafner EXODUS" is currently airing, the first half aired in January of 2015, with the second half coming in October of 2015.

The Empire of Brittania has invaded Japan using giant robot weapons called Knightmare Frames. Japan is now referred to as Area 11, and its people the 11s. A Brittanian who was living in Japan at the time, Lelouch, vowed to his Japanese friend Suzaku that he'd destroy Brittania. Years later, Lelouch is in high school, but regularly skips out of school to go play chess and gamble on himself. One day, he stumbles on terrorists 11s who've stolen a military secret and is caught by a member of the Brittanian task force sent after them, who is Suzaku. As the rest of the squad arrives, Suzaku is shot for disobeying orders, while the military secret, a young girl, gives Lelouch the power to make anyone obey any order. He takes command of the terrorists and leads them to crush the approaching Brittanian force. However, Suzaku is secretly made the pilot of Brittania's brand new test model Knightmare, Lancelot. Lelouch becomes the masked king Zero to lead the rebellion to defeat Brittania. This series follows Suzaku's side of the story, while Lelouch of the Rebellion follow's Lelouch's.

Kenichi, a 20-year-old man, took an entrance exam into college, but fails it for the third straight year. That day, he came across a traffic accident where it appeared that a giant robot went crazy and disrupted the flow of traffic. He meets a person by the name of Mitchy who is trying to save the remaining survivors. Who is this Mitchy person and what does this "Red Party" fraction have to do with the giant robot?

Kidou Ryodan Hachifukujin is set in the near future where Japan has been subjugated by China and now fights against its former ally America under the Chinese banner. Fukujin, literally “luck god,” are special armor suits that are impervious to most conventional weapons. The story follows new recruits in the army of Japan, in a war torn future. There's an eccentric girl, a pacifistic guy, an advanced suit of armor impervious to all weapons figure in a story about war, violence, and militaristic subservience.

A series of short stories that take place throughout the Universal Century Era. (from Baka-Updates)

Manga version of the same-name anime.

College freshman, Seiji Murayama, is living on his own for the first time until an enormous cyborg from his past appears in his closet.

Updating

/ from the A-Team / Eraser, the mysterious enemy that invaded Earth 13 years ago!! Before their overwhelming power, the entire Earth neared the verge of collapse. But at the last moment there suddenly appeared Earth's lone savior, The Beast: an ultimate weapon uniquely equipped to counter the Eraser's power!! The Beast is part of the MAGIC Brigade, whose commander-in-chief is also the founder of our Le Prince Academy... Ladies and gentlemen, I present to you, Mr. Vincent!

From: Easy Going Scans A Demon Lord spirited the Princess away, and cursed her with eternal sleep. Countless knights sought to save her, only to die in vain by the Demon Lord’s hands. But then, a Nameless Knight arrived to vanquish him and save the Princess, ignorant of what fate had in store for him...