This thread is lol. If we're going for influential rock artists, you might as well throw Chuck Berry on the wagon and call it a day.
But in all seriousness, this poll is damn tough: all of these artists contributed or influenced rock in some distinctive way, and not just in sound. The 60's was also that fun little decade where all sorts of nifty techniques regarding production and recording came about as well.
But w/e, Hendrix gets the vote. I'm very fond of riff distortion after all.