The grandaddy of all giant robots. Mitsuteru Yokoyama's Tetsujin No.28 or as he is known in the west – Gigantor. The above clip is taken from 1980 remake. The original show started in 1965. There was sequel in 1992. Another remake in 2004 (by Giant Robo's Yasuhiro Imagawa). And a live action motion picture in 2005.
It's just one of those shows whose influence is immeasurable both within animation and outside it. It's the first show in the Robot anime history reel and the reason there are 13 parts to the reel is due to the impact of Gigantor (and due to the second show on the reel the previously mentioned Mazinger Z – lets give that show it's dues even if this chart didn't).
And it's probably one of the most important anime shows in the English speaking world too as it's one of the shows imported to the US by Fred Ladd in the sixties.