Has any of you remember and had watched Astro Boy?  

For me I consider this one a classic! I think I had watched this series when I was still in my grade school years;)
Astro Boy is the first Japanese television series that embodied the aesthetic that later became known as anime. It originated as a manga comic series started in 1951 by Osamu Tezuka, who is known as the "god of manga".
Astro Boy is a science fiction series set in the future where androids co-exist with humans. Its focus is on the adventures of the titular "Astro Boy", a powerful robot created by the head of the Ministry of Science Dr. Tenma to replace his son Tobio. After Tobio died in a car accident, Dr. Tenma built Astro in Tobio's image and treated him as lovingly as if he was the real Tobio, but soon realized that the little android could not fill the void of his lost son, especially since Astro could not grow or express human aesthetics. Later Astro naively signed himself away to a cruel circus owner. While Astro languished in the circus, Professor Elefun, the new head of the Ministry of Science, noticed Astro Boy performing in the circus. He managed to take Astro away from the circus and brought him along and treated him gently and warmly, becoming his legal guardian. He soon realized Astro was gifted with superior powers and skills, as well as the ability to experience human emotions.
Soon, Astro Boy became an android super-hero with a variety of special powers. Astro then fought crime, evil and injustice.