The two most important bands in hardcore punk history are the Bad Brains and Discharge. If you disagree with this fact, you're wrong.
The Bad Brains took the American punk movement and made it into hardcore. More often than not, you can't actually quantify the difference between hardcore and punk into sonic terms. Especially when it comes to the first wave of USHC. The Bad Brains presented the formula of harder, faster, and meaner. There was something to be seen from what they were doing in DC. In the course of their time, they inspired the scene around them to step up. Because of that, we got the early DC scene that included Youth Brigade, Void, and Minor Threat. Eventually the Bad Brains were "banned in DC" by 1979 where they picked up and left for New York City. Now boasting the Bad Brains, New York City's hardcore punk scene exploded almost overnight. The band showed kids how it was done and the entire scene rose to the challenge of keeping up with the Bad Brains. Almost overnight bands like the Cro-Mags, Beastie Boys took cues from the Bad Brains while kids wanted to play harder, faster, and meaner. While Bad Brains was causing the scene to undergo a renaissance, back in DC the hardcore punk scene was already entering its twilight years. By the mid 1980s, much of the DC scene's first wave of hardcore would be broken up. The best way to explain the Bad Brains's importance to USHC history is to look at them like a foundation. Where they went, they laid down the groundwork that others built themselves on top of. In DC they were the city's foundation (HR famously claims that it was him to tell Ian MacKaye to put himself out there more with Minor Threat). Once they left, the scene stayed up for but a few years before collapsing into post hardcore (something that would eventually happen to NYHC in the late 80s). They arrived in New York where they laid down the basis for the greatest hardcore scene of all time. Without the Bad Brains, NYHC never really happens.
The point of explaining the Bad Brains' importance is to better understand Discharge's importance. While the Bad Brains were the 'foundation', Discharge were the disease. Their influence is not something that people have built on top of. Rather it is something punks have spent thirty years trying to reinterpret, distort (sometimes literally), and co-opt Discharge's iconography, aesthetic, and sound.
Whereas Bad Brains' influence is limited mostly to the DC and NYC areas, Discharge's infection spread across the world like a plague with varied results. It's interesting when you look at the global punk landscape and see what Discharge wrought from it. Without them, we don't have Swedish or Japanese punk as we know it. The US crust punk scene would also be markedly different. There are punk legends that have made entire careers in pursuit of Discharge's mantle such Disclose and Anti-Cimex. The band took the most basic concepts about war, death, and society and hammered home a sense of futility and nihilism to all of it. While the anarcho bands were preaching about a call to action, Discharge was making it very clear that all the rallies and votes in the world won't change the fact that you will never get a say in society's workings and if the war has to come to kill you, so be it. Anger borne from society and politics shouldn't illicit apathy, but it does. That's part of Discharge's magic. A sort of kamikaze spirit that has come to terms with the fact that we will all die and that our control of this death is minimal. It speaks more to the solider fashion (and typically reckless lifestyle) that many punks take on.
The band's golden era runs from 1977 - 1983. The lineup included Anthony "Bones" Roberts on guitar (who would leave in 1982 to start Broken Bones), Royston "Rainy" Wainwright on bass, Terrence "Tezz" Roberts on drums (the man who is often credited for innovating d-beat in punk), and Kelvin "Cal" Morris on vocals. These were the four major members (the band has famously had a revolving door of personnel for the last three decades). In that period they produced two albums, five EPs, and three singles. The full length albums Why? and Hear Nothing See Nothing Say Nothing are classics, only worth comparing to each other. Those six years of Discharge are without measure or peer. Some punks will spend their entire lives trying to understand and recapture what the band was able to produce in that time. There's a reason why the Never Again dove, the Decontrol face, and the rest of Discharge's iconography ends up everywhere to this day. They are a disease. One that continues to inspire kids and scenes around the world. No one will ever be Discharge again, but in the course of trying, amazing bands will happen.
Included are both full lengths and all of their EPs / singles under The Clay Punk Singles Collection compilation. Download these. Learn them. Hear them. There is only one Discharge.