Getting near the edge, but I'm nominating the Violent Femmes.
The Violent Femmes are classic for sure but when I think punk rock, it really starts with Black Flag. The first album I ever bought was My War and as crappy as it may sound to some, this thread sure brings back memories! Black Flag aside, my favorite punk band was Agent Orange and I actually have Sonic Snake Session playing in the background now.
Agent Orange - Sonic Snake Session Black Flag - My War 
