Punk rock changed my life...but then again, to some people if it's not the Old 97's or some alt-country thing, it's shite. Not that I care, because I don't care much for that attitude anyway. Punk rock MAJORLY altered popular music in the 70's, 80's, 90's and 00's. It may have been a trickle-down effect in a lot of cases, but it's there, in everything from Blondie and the Go-Go's to Green Day and Nirvana.
For my own pick, I would say the 3 I would choose EASILY are the Stooges, Patti Smith and Grandmaster Flash. Fourth would be the Pretenders. You have to give credit where credit is due...the Stooges put out three of the best rock'n'roll records of all time. The Sex Pistols, though influential, also did as much damage as they did good. Nobody wanted to touch punk rock after the Pistols. Bands like the Ramones were pretty much destined to commercial failure because the image was too risky to record labels. That's why people started signing up all the new wave bands because it was watered down punk and it was more palatable to the consumer.
That being said, punk rock is class music like the blues or country. It was meant to be about rebellion, and it was inspired by people who were beaten down and tired of it. Their expression was through music, and there is an honesty in that type of music because it's inspired by what is real. Not all punk is sophisticated (let's face it, people like the Ramones were NOT society's elite), but there was still something that fueled their songs...and over time it became more focused, more angry. Put on any early Black Flag, Minor Threat, or go back to the Stooges. You have a revolution in those records. The Stooges are the real deal...they belong in the Hall of Fame to give it some legitimacy.