"Densetsu Kyojin Ideon", also called "Space Runaway Ideon", is a Mecha-Anime-series from 1980 which consists of 39 episodes. It was directed by Yoshiyuki Tomino, also known for other Mecha-series like "Gundam" and "Heavy Metal L-Gaim".
Basic plot: During an attack on planet Solo, a group of people discover the ruins of a long dead alien civilization, a three-part combat robot called "the Ideon", and later a huge, powerful spaceship. After the "Ideon" and the spaceship (now called the Solo Ship) suddenly get activated, the crew on the Solo Ship (now in space) get constantly attacked by a group of pestering but powerful aliens called the Buff Clan, who are trying to get a hold of the "Id", the mysterious energy which powers "Ideon".
Just after watching the first two-three episodes, I just got hooked on this series. For something released on Japanese TV in very early 80s, nearly each episodes have lots of intense battle sequences which should satisfy any fans of combat-robot-anime, and the Mecha-animation is just as great as it could be. The soundtrack was pretty great, and fits perfectly for not only the combat scenes, but also most of the scenes of other stuff like dramatic, mystery and tragedy. Upon watching this anime, I got sympathy for most of the crew on the Solo Ship, including Cosmo Yuuki, Karala Ajiba and Sheryl Formosa just to name a few.
Originally, 43 episodes were supposed to be aired on TV, but due to low ratings, the rest of the series was cancelled after 39 episodes. Following said cancellation, due to demands for the remaining four episodes, two movies were made: The first one named "The Ideon: A Contact" is basically a summary of the first 32 episodes, with a few additional scenes only made for the movie. "The Ideon: Be Invoked" however contains the final unaired episodes which should end the Ideon saga once and for all.
Such a great anime this is, this one highly deserves to be released outside Japan where it was made, and I should wish that more people (mainly fans of Gundam-like Mecha-anime) would get to discover and eventually watch this masterpiece at least once. My overall rating is a full 10/10.