Brave Bang Bravern!

Bang Brave Bang Bravern</I> is set in a world where humanoid armored weapons known as “Titatonostrider” (“TS” for short) are used in warfare. The story kicks off when troops from various countries converge on the island of Oahu, Hawaii, including the main characters, Ao Isami of the Japan Ground Self-Defense Force and Lewis Smith of the United States Marine Corps. Isami and Smith cross paths during battle, but suddenly their teams are attacked by an unknown enemy, scattering soldiers and sending their forces into disarray. In order to save their friends and survive on the deadly battlefield, they must fight with every ounce of courage and pride that they can muster. (Source: Crunchyroll News)

VOLTES V

From out of nowhere, a mysterious alien race known as the Boazan Forces has invaded the Earth. A group of individuals specially trained to handle this kind of situation has been unleashed. Kenichi, Ippei, Daijirou, Hiyoshi &amp; Megumi are the pilots of the Choudenji Machine Voltes V (5), Earth's defense against the Boazan and their terrible Beast Warriors. The plot thickens as the Go Brothers discover their true heritage and the truth behind their father's disappearance. Conflicts and mixed emotions hinder the Go Brothers at times but due to their unwavering desire to find their dad, they must go to the place where it all started. With the help of the rebels based on Earth and on the aliens' homeworld, the Voltes Team has another mission, remove the tyrant Zu Zanbajil and liberate the people of Boazan. (Source: Anime News Network)

Blue Comet SPT Layzner

The SPT Lazner is a super-powered, computerized Tracer robot. It is the strongest robot in the universe. The story's hero, Eiji, is the child of an earthman and an alien from another planet. He happens to find out about a conspiracy to destroy the earth. Using Lazner and with his friends’ help, Eiji decides to save his father's planet earth and fight against his mother's planet to achieve peace in space. The Story takes place in an alternate reality based in the year 1996, where humanity is advanced enough to develop long-range space travel.</i> (SOURCE: AnimeNewsNetwork)

GoShogun

A meteor strikes the Earth and is found to emanate a powerful new energy called Beamler, which is used to power a battle robot, GoShogun, and a teleporting fortress, Good Thunder. The Docougar Crime Syndicate, lead by crime lord Neo Neros, try to steal the secret of the energy from the inventor of GoShogun, but he kills himself rather than let them acquire it. His son is targeted by Neo Neros next, but he is taken in by the crew aboard Good Thunder, who travel the world fighting NeoNeros's forces with GoShogun. (Source: Wikipedia)

Koutetsushin Jeeg

Kotetsushin Jeeg takes place fifty years after the original and features a new cast of characters&mdash;primarily the new main character Kenji Kusanagi, a high school student who becomes Kotetsushin Jeeg to fight the sudden reappearance of "Haniwa Genjin" ("Haniwa Phantom Gods", or clay robots) from the Jamada Empire ruled by Queen Himika. Other characters include Tsubaki Tamashiro (grandaughter of Miwa Uzuki); and Kyou Misumi. Other main characters from the original series also appear.

Gunbuster

In the very near future, a race of huge, insect like aliens is discovered traveling the galaxy. These aliens seem dedicated to the eradication of the human species as it takes its first steps away from the solar system, and they are getting closer and closer to Earth. Humanity has responded by developing spacegoing battleships and giant fighting robots. These robots are piloted by the best and brightest of Earth's youth, picked from training schools around the world. The story begins in the year 2023, not long after the first battles with the aliens, and centers on young Noriko Takaya. Although Noriko's father was a famous Captain in the space fleet who was killed during one of the first battles of the war, her own talents as a pilot are questionable. Nonetheless, she has entered a training school. Through the series Noriko, joined by the beautiful and talented Kazumi Amano, will fight to overcome the trauma of war, the doubts of her peers, and her own lack of confidence. (Source: AniDB)