I call it Sherlock-esque. Or Hercules-esque.
Hercules, in an archetype shared by Gilgamesh, Superman, and Sherlock Holmes, is a super-human. Far superior to mortal men, he leverages his ability to overcome obstacles in a way that celebrates his abilities and, to some degree, proves him worthy of having them. Golgo 13 is a character like this.
Of course, the more common comparison would be to James Bond, who does share a certain level of tacky suavitude with Golgo, but truthfully the anime is more focused that the usual destructive spy rampage at the end of any good Bond movie. It revolves entirely around master hitman Duke Togo (Codename: "Golgo 13") and his ability to shoot people. As with Sherlock Holmes ability to pierce the criminal veil, Duke is infallible in his ability to follow through on contracts. His modus operandi is a long distance shot made against sometimes absurdly poor conditions with a modified M-16, always with perfect accuracy. Realistically, very few of Togo's shots are possible but this fact is irrelevant; the real mystery is how and why the bullet lands where it does.
The stories are moody and personal, commonly involving family members taking contracts out on one another, or lovers or business partners. Barring the rare occasion when Golgo is hired by legitimate authorities under the table, Golgo will inevitably fulfill their wishes to their own exacting specifications and escape... but there's always a price paid. Sometimes, redemption is found. But usually, justice is served, harshly. The survival rate for Golgo's clients is spotty.
It is, obviously, a tightly formulaic show. Golgo suffers from the Superman dilemma of writing; where does the character go if he's always going to win? If no one can match him, who does he fight? The answers of course eventually run into novelty but the best option is to apply symbolism. Just as Superman has exploitable themes, so does Golgo 13 and the show actively plays them up; Golgo is short for Golgotha, the hill on which Jesus died and Golgo's brand is literally a skeleton hanging from a cross, the message apparently being the difference one death can make. And, true to form, death comes to at least one person in every episode of Golgo 13- in one particular episode, Golgo is taken to an Alcatraz-like prison. Once inside, he becomes involved in a fight that gets his sentence illegitimately kicked up to death row by the corrupt warden. Now in a solitary cell, he befriends the prisoner in the next cell over and formulates an escape plan over the course of weeks. The two make an incredible escape against typically impossible odds and as they are making their way to shore, Golgo shoots the man. Why? Because someone wanted him silenced. Then it fades to black.
Cliche? Maybe. This show deals shamelessly in cliches, and is full of ruthless gangsters, loose women, do-the-right-thing cops, and back-alley thugs. If you are sensitive to those things, I do not recommend it. But if you can appreciate a story told over and over again yet different every time, Golgo 13 is for you.