No other band touches or contains as many different facets of American music–in addition to having their own idiosyncratic, yet quintessentially American thing.
Dead lyricist Robert Hunter said, "The best compliment I ever had on a lyric was from an old guy who’d worked at the Cumberland mine. He said, ‘I wonder what the guy who wrote this song would’ve thought if he’d ever known something like the Grateful Dead was gonna do it.’ "
I voted Grateful Dead for music culture influence, and would vote Hendrix for his influence on British Invasion but his trio isn’t a band I guess. Bands like the Band, Buffalo Springfield, R.E.M., the Eagles deserve mention for their Americana, Beach Boys for Brian Wilson’s mad genius, and Rush for being the main North American prog band along with Kansas. Simon & Garfunkel had a large cultural influence but a duo isn’t qualified as a band. Then there’s singletons such as Elvis, Bob Dylan, B.B. King, Professor Longhair and Dr. John, but that’s for another poll.
I’m just here to say I get to meet ZZ Top later this week! 
The Beach Boys would surely be leading this poll if not for that sticky requirement that “they rock”. In terms of longevity, Americana, and influence on other groups, I don’t think there’s anyone close.
If Bruce is counted, then surely Madonna is counted too. So my vote goes to Madonna.
really surprised nirvana is not doing better here
I’m a huge Nirvana fan and I think they were one of them most influential and game-changing bands in the history of rock. But I just don’t think they were around long enough to be called the greatest.
I agree with every word of this.
I’d vote for X. I saw them live, still have them in iPod rotation.
B o c! B o c! B o c!
Black Flag. They aren’t even a favorite, but they got the ball rolling.
The Beach Boys and it’s not even close.
I’d be very curious to see a breakdown of the ages of the people voting in this poll.
Anybody under 40 should be disqualified from voting. They never got to see the good bands. 
Zappa and the Mothers – not just for what they did but for the others they helped along like Captain Beefheart and the GTOs.
They had 3 major albums though… isn’t that enough?
Nirvana didn’t have wide appeal. They were the voice of a very small generation, mainly those who came of age in the early 90s.
Many of the other bands on that list draw audiences of all ages 30 years after their commercial prime.
First of all, with statements like this is it any wonder Generation Y and millennials feel marginalized by Gen X?
Second of all, how may other bands on the entire list could be called the voice of an entire generation, of ANY size?
Thirdly, what makes you think Nirvana didn’t have wide appeal? Nevermind sold 30 million copies!
Because the list did not include either Blood Sweat and Tears or Three Dog Night, I had to select “Other”.
Sigh.
Slight hijack, here, but if any group has been marginalized it would seem to me to be Gen X - being I’ve shadowed by the Boomers and Millenials (I consider Gen Y to belong to either Gen X or Millenial, not their own group).