Golgo 13? Did you meant the Japanese Chuck Norris?
Duke Togo is the best hitman in the world but not only that. During the anime we understand that he is also the strongest man on the planet.He goes through all different types of missions and manages to complete them.
Every episode consist different story which has nothing in common with the one before and don't follow any route.However in every episode Golgo proves himself in every aspect of killing.If in one episode he kills someone from 2 km using a rifle, in the next episode at night he will kill 5 trained soldiers using no nightvision and only his m4.
I really didn't liked the story because they never reveal Golgo's past and how he became the man he is now.
The opening and ending are very good and you will most likely be able to sing them after you have finished the anime.
Most of the time you will rely only on the sound or image to understand what happens or get hint about the way Golgo assassinate its target.
If you like animes where the main character doesn't have a character development that's probably just for you.
I really enjoyed watching it. Every episode shows Golgo's dedication to be the best in the word. He won't fail a mission to save a woman he loves.
The main reason i didn't like the anime that much is that the episodes were a little repetitive and they never revealed his past.