The sheer level of skill, cunning and intelligence Golgo displays deserves a mention. Not only does Golgo have all of the proper abilities required to be an assassin, he excels at them. In addition to his physical prowess and lightning-quick agility he has proved time and time again to have a genius level intellect in the methods and strategies he uses to go after his targets. He knows how to avoid and minimize risk, plan his targets moves well in advance and always does his research to find a way to achieve his goals. You want to hide behind half a foot of bulletproof glass? Golgo will focus all of his shots on a single point the size of a pinhead to drill through it and nail you with a killshot. You want to step inside a secure panic room with steel walls? He'll find a way to draw you out into the open where you won't even see him coming. You want to hide in some sort of maximum security prison surrounded by guards? He'll either find a way to get inside or shoot you through a tiny opening that only appears for a split second on any given day of the week. Duke Togo isn't a dangerous man because he can hit a target at an impossible range or because he can take on an army and win. He's dangerous because he has a cold emotional detachment that would make a Terminator jealous and can keep a cool head even in the most dire situations. He isn't just strong, he's smart... logical... and never lets his guard down. Most of his victims never even see him coming until he has a lock on them... and some don't see him coming at all.
Speaking of Gold & Silver they deserve a spot here as well. While they may not be quite as deadly or depraved as Snake both are shown to be similarly unhinged and dangerous in combat. Dressed in matching attire with prosthetics made from their namesakes the duo are challenging opponents that come close to finishing off a heavily injured Duke Togo before he can reach Leonard Dawson himself. Gold manages to grab ahold of Golgo's bullet wound and very nearly tears his stomach open with his golden gauntlet before getting his head smashed in and then filled full of lead. With his partner dead Silver is then shown crying Tears of Blood while preparing to ambush Golgo, which he does in one final desperate charge as his mask cracks apart to reveal his horrifically burned face. Thinking quickly, Golgo shoves a grenade in his mouth and blows his entire head clean off his body as his remains are enveloped in flames, putting an end to the demented duo once and for all. They may not have gotten as much screentime as Snake but the nightmarish pair are sure to leave a lasting impression in many viewers minds long after their demise.
Their backstory is just as nightmarish as you'd expect from such a twisted pair and perfectly explains how they turned out the way they did:
Dr. Z. A mafia boss willing to kill civilians and children is one thing. Now imagine said boss living in a seaside mansion guarded by the best gunmen in Sicily, and no man alive can ever claim to have seen the doctor. While it is revealed that Dr. Z is actually the gorgeous Ms. Fanservice Cindy, let the horror sink in that a beautiful young woman had ordered the massacre of countless innocents in the name of business. And that's not all, because Cindy's no innocent girl herself while pretending to not be Dr. Z; she has a habit of having the men she's slept with killed after she's done with them.
Lieutenant Benning. Good Lord, where to begin? It's like the writers decided to read the entire Sociopathic Soldier page and condense it all into one character! Benning may have ultimately proved to be small fry compared to some of the guys Golgo has faced over the years, but he makes up for it in sheer depravity and ruthlessness. Called in by a corrupt general to kill Queen Bee by any means necessary Benning leads a band of soldiers on a raid of her home village, killing many noncombatants in the process. But even with the atrocities he commits onscreen it's implied to be nothing compared to what he got up to during the war...
While nowhere near as psychotically violent as Benning is, Thomas Waltham also is pretty creepy by himself. Not only did he have Robert Hardy's mistress murdered, he also raped their 10-year old daughter.
The Manga and 2009 Anime
Ross MacDonald and Ingmar Pettensen, Golgo's targets in "The Brutes' Banquet" live up to the title. Enthusiasts of human blood sport, they once led an army of mercenaries to massacre an entire village of innocent people. Then they fed the last survivor, a little girl, to pirannas just to see how long she'd last.
Volume 5 of the Viz release regales us with various tortures Golgo's faced. Some of the more horrifying ones include him being attacked by tsete flies, attacked by a giant eagle in the desert (under the midday heat and with nothing but pants on and his fists to fight with), and being made to listen to music at deafening volumes after three days of continual whipping.
"The Serizawa Family Murders" is pure Nightmare Fuel from start to finish. A multiple unsolved homicide? Check. A decades-old case involving a family of assassins? Check. Golgo's sinister shadow hanging behind it all? Double check.
"15-34" has Golgo's target be of all things, a rogue AI system codenamed "Jesus". Unfortunately, this particular AI system hacks into the FBI database and comes to the conclusion that Humans Are Bastards. Thusly it tries to hack into the US defense grid to activate the entire US nuclear arsenal to cause an apocalypse.
"Hydra" has an enhanced form of heroin that permanently damages peoples' minds. The Professor Guinea Pig who invented it (and hides her true self under a male nom de plume) suffers from a host of induced mental disorders and ends the arc crawling on the ground babbling about how she cut off her own head but another one grew in its place. Golgo's been contracted to assassinate her, but at this point it comes off as more of a Mercy Kill.
"Garimpeiro" (episode 21 of the anime) opens with a violent gang raiding a small isolated Brazilian village and going full Rape, Pillage, and Burn on the inhabitants. After most of the residents are dead the thugs then make off with several of the village women, leaving the entire place in ruins. A lone man then returns from fishing to find his family either dead or kidnapped and his home gone. It's soon revealed that the captured women were raped and killed and the man himself was fatally wounded trying to avenged them. Driven mad by the trauma and the pain of his injuries the man presents Golgo with some diamonds he stole with a crazed expression before finally expiring after begging him to take the job. Golgo ultimately decides to do it and brings the culprits to justice, but its a small comfort when considering that he wasn't able to actually save anyone from the village.
In the manga, a few of Golgo's clients are children. God knows what kind of people they'll grow up to be...