Mazinger Z is a classic of the mecha genre. This anime introduced many concepts which we see at any mecha anime, for example: The robot is the last hope of humanity, being piloted by a human (preferably teenagers), mad scientists trying to conquer the world, cronies incompetent or strange-looking people, a proud pilot woman (do you remember Asuka?).
In each episode is the same plot: Dr. Hell sends his Mechanical Beasts, Koji Kabuto runs to Mazinger, background music resounds, and the battle begins. Many emotions and feelings are mixed in the battle, but in the end, Mazinger is the winner.
I saw this anime in the 1980s as a kid and I still like it. If you like the mecha genre, you should see this anime.
I know these words are not enough to describe it and see it as an adult is not the same when you were a child. This is my humble opinion. I hope you find it useful.