Street Samurai

The Street Samurai is the classic protagonist archetype in Cyberpunk and Post Cyber Punk, but also shows up on occasion when those genres are mixed with Dungeon Punk and Urban Fantasy. Hackers, warriors, and anti-authoritarian loners, these characters fight against the dystopian governments, and Megacorps that rule their worlds. They are down on their luck souls that Walk the Earth because their own personal codes of honour make refuse to sell out to the authority. Typical goals for this sort of character are Information Wants to Be Free, and bringing down the very society in which they live in order to make a better one.

They are the tech-savvy mercenaries, bounty-hunters, assassins, bodyguards and general badasses of the urban jungle. They're far cooler than standard Mooks, often sporting a Badass Longcoat, Cool Shades and other stylish gear. Edged weapons are common despite being strange for the era, and Katanas are recommended, but not mandatory. Street samurai by no means eschew firearms however, and are frequently expert gunslingers, but expect Cool Guns and Abnormal Ammo. In classic Cyberpunk, the samurai would often be heavily augmented with cybernetic parts, but this is no longer mandatory. Hacking, at least at a rudimentary level, or other similar tech skills (creating prothetics, building custom weapons systems and vehicles etc.) is required.

Despite the name, these characters have a lot more in common with Ronin and sometimes Ninja than they do with Samurai, being essentially descendants of recognizable types drawn from hard-boiled private-eye literature and Film Noir.

Compare Samurai Cowboy and Corporate Samurai. Note, that merely having the toys of a Street Samurai does not make you one if you don't have the personality and skill set. Not to be confused with the Steel Samurai.

Examples of Street Samurai include:

Comic Books

Ronin is probably the Trope Codifier for comics.

Film

Being inspired by Neuromancer, the human protagonists of The Matrix exhibit characteristics of this, especially Trinity.
The eponymous character from Ghost Dog is a gangster hitman who lives by the code of Bushido and has a number of anachronistic habits, such as communicating by messenger pidgeon. RZA has a cameo as another one of these.
The protagonist from Le Samourai. Besides the title, it gets points for having a protagonist who wears a Badass Longcoat. And it was an inspiration to John Woo (hence the gun-slinging and Cool Shades elements)
Kill Bill: The Deadly Viper Assassination Squad is a group of assassins, some of whom use katanas. While The Bride is in a coma for several years and Bill is in semi-retirement raising their daughter, the group disbands and the members either retire or work solo, essentially becoming Ronin.

Literature

Molly from Neuromancer and other works by William Gibson is the Trope Namer and Ur Example.
Hiro Protagonist in Snow Crash is a pizza deliveryman and freelance hacker, but his combat skills, talent for working high-tech espionage, and willingness to take on enemies far larger than himself to do what's right are what make him an example. Raven does work as a mercenary, but he's got his own agenda.
Neal Stephenson's The Diamond Age has a Decoy Protagonist, Bud, who behaves a bit like one of these. He's mostly just a street hoodlum who spends his money on bionic weapons. He's messily executed in short order.
Sri Death from Tais Teng's Memoirs of a Matriarchy and Neon Moon anthologies. Though he is practically invulnerable and possibly immortal by the end of his arc, he still suffers from Badass Decay to make the point that the universe is ruled by forces greater than any single person can control.

Live Action TV

Future Hiro in Heroes has the jacket and katana in a Crapsack World and seems to be this type, as well as a Shout-Out to Hiro in Snow Crash.

Music

The Disposable Heroes Of Hiphoprisy song, "Satanic Reverses" has a line:

Sent Joey to the Supreme Court
Cause he made a statement, they called it
Desecration of the symbol that was meant to represent
The freedom of so-called choice and dissent
They almost had me believin' it, I was bleedin' it
He said, "Burn, baby, burn"
Til the Street Samurai said to my face
That any flag that's worth shit
Was woven from fire in the first place.
In this context, the "Street Samurai" is likely Rono Tse, fellow Disposable Heroes of Hiphoprisy bandmate.

Tabletop Games

Shadowrun uses this name for one of the classic runner archetypes, specifically the independent fighting guy who augments his abilities with lots of cyberware. Fighters who augment themselves with magic, who augment themselves with corporate backing, or who rely on pure skill rather than augmentation, do not fit this definition, although those who use biotechnology instead of cyberware do, oddly enough.
Any Solo in Cyberpunk2020 would count.

Video Games

There's an obscure PlayStation 2 game called Seven Samurai 20XX based on the Seven Samurai set in a cyberpunk world.
In SNES classic X-calibur 2097 the player character is this; same well for his Evil Twin brother.

Web Comics

Dechs, the title Antihero for Hire.