Black Sabbath invented heavy metal. You know you're doing something right when you invent a genre of music.
There are two kinds of people in this world: the kind that don't "get" Jack White, and the kind that love every piece of music that he's ever made. I am the latter.
The only reason that Primus did not invent a genre of music, is that there isn't another band that is talented enough to follow in their footsteps.
The Beatles are only the most influential band in the history of music. So, while Sabbath invented and influenced metal, The Beatles influenced every genre in existance right now. That's really not an overstatement.
William Eliot Whitmore is a bit more modern, but the reason that I cite him as an influence, is because he doesn't sound like anyone else. He may not be a legend, but it doesn't matter if you have the talent.
Bob Dylan was not a particularly good singer, but I think that's why people liked him. Song structure is important, and is a talent in and of its self. Dylan proves this concept.
I'd say that Tom Petty is more of an excellent song writer, much like Dylan. People compare me to this guy every time I grow my hair out, so I obviously had to cite him as an influence.