Giant robots predate modern manga in Japanese pop culture, but early on, they were generally the tools of evil mad scientists. Mitsuteru Yokoyama's 1956 manga and 1963 anime series Tetsujin 28 popularized them as heroic. Except for the 70s, there's been an anime remake every decade, most recently in the 00's by Yasuhiro Imagawa (G Gundam).
For the 2010s, we're getting Tetsujin 28-gō Gao!, a series of shorts recasting the story of a boy detective and war time weapon as a slice of life comedy. The series is slated for April.