Elvis Presley, from as objective a POV as possible. No one's ever towered over music like he did in the 50s. The Beatles, Velvet Underground and The Stooges are also very influential on the artists that followed, but Elvis popularized rock. Bill Haley, Chuck Berry, Buddy Holly and others were very good, but Elvis dwarfed everyone else in popularity.

Popular and influential aren't really the same thing though.

Rock owes a debt to that popularity. He put the genre on the map and influenced a wave that followed. Why do you think pretty much every rock artist ever has cited him as a influence? In this case, popularity is influential, as is the case with Michael Jackson. He was so popular that the music industry changed from then on. The Beatles can't touch the impact Elvis had on rock. Thats why he's The King.

Also, no Black Sabbath? Pretty much every heavy music artist is heavily influenced by Sabbath.

Well a popular artist is more likely to influence a large amount of people than an unknown artist. If an artist is unknown and nobody has Ever heard of them, how are they going to be influential?

I disagree with the notion that The Beatles can't touch Elvis. Elvis did put it on the map but the Beatles were so huge that they are comparable with Elvis. They're two of the biggest names in music.

I think Sabbath belongs on the list as much or more than the Who and The Kinks.

Just because someone isn't as popular as Elvis doesn't mean they're unknown. And influence isn't just about the total number of people listening to the person in question, it's about who those people are. As the famous quote goes, "The first Velvet Underground album only sold 10,000 copies, but everyone who bought it formed a band."

That's a nice cliche, but Elvis influenced pretty much every rock act that came immediately after, and continues to do so today. His popularity just made him even more influential. However, influence is not quantifiable, so I can't really go beyond that.

I didnt say they had to be as popular as Elvis.

The beatles sold millions of records and inspired more than 10,000 bands. The VU did as well but the Beatles were more influential And they inspired plenty of great bands. I love the VU and they are pretty overlooked in the mainstream, especially in their time, but the Beatles made quite a bit bigger impact.

Cliche? In what way? Do you deny that artists can be extremely influential without being the number one sellers of their time?

I'd love to hear some examples of this influence which can be specifically attributed to Elvis as opposed to, say, Bill Haley, Chuck Berry, Carl Perkins, Ike Turner or Little Richard.

I didn't say you did. I was just making the point that "not as popular as Elvis" is not the same thing as "unknown" as you seemed to be implying.