I agree with Hendrix being number one... What he did to guitar is something no one else had ever done, and it still sounds innovative today.
Cobain shouldn't even be on the list. He has a cool style, but he's a shitty guitarist. I'm a nirvana fan, but lets be serious here, there are so many better guitarists out there.
Frank Zappa is fucking nuts, and should be way higher on the list.
The whole genres of jazz and classical were pretty much overlooked... so the most technically advanced guitarists out there don't even get mentioned.
Adam Jones (tool) is better at keeping time than everyone on this site is at growing combine. Tool is absolutely nuts.
Johnny Greenwood (radiohead), one of the most musical guitarists there is. Extremely innovative and very pleasing to the ear.
Is buckethead on there? Buckethead is like a guitar superhero.
David Gilmore & Syd Barret, if you don't like pink floyd you just might be retarded.
George Harrison, probably one of the best guitarists ever. Only guitarist in a popular band without a huge ego. He did everything for the song, and never showed off. Hats off to him.