Left,left,left,right,left
Yes ,I am in lock step with the Jimi Army. Hendrix was very famous for being a left hand guitarist. Look at any image of him and you will see that upside down righty Strat strung left handed. The image of the upside down,large,CBS style headstock is such a classic image associated with 60s psychedelic music,Woodstock,and Mr. James Hendrix. He was famous enough to inspire generations of guitarists with his innovation and style. While his style may have been his #1 innovation his status as a lefty is such a big part of the image that is ingrained into his fame. He even inspired the developement of a model of Stratocaster with lefty neck and reverse slant bridge pickup to try to recreate his unique sound from his lefthandedness. All for right handed players that can't make the high fret stretch with the upside down body but want the Jimi mojo. We were just beginning to see the depths of his talent when he passed on.
There may be other very notable left handed guitarists but none that can match Jimi in all those catagories.
It never really occured to me that Albert King and Dick Dale were lefties. Two great talents. McCartney is definately a notable lefty but can't top Jimi on the list.
While not in the same ballpark for widespread fame or being noticed as a lefthand guitarist, I have to give Otis Rush an honorable mention for his talent and innovation. If you listen to what he was doing in the period of 1956-1963 or so he was very much an innovator well ahead of his time. He is not underated by those who know and listen to him but he doesn't really get the credit deserved. He was a big inspiration for some of the best such as Hendrix ,SRV ,and Jimmy Page. It's funny that we have guitar players coming onto the scene now who derived their licks from guys like Kenny wayne Sheppard,Chris Duarte,John Mayer,(and the like) who derived their licks from guys like Hendrix,SRV,and Page who derived alot of their licks from guys like Albert King and Otis Rush. Not that it is exactly linear. There is much cross generational influence going on within that line. What it boils down to is this: Listen to Otis Rush from the early days and you will hear many familiar licks and rudiments that are on new or fairly new blues rock songs that sound fresh and cutting edge today. For this reason I have to vote for Otis Rush as the stealth candidate for most influential left handed guitarist.
IMHO
Jimi Hendrix is the most overtly famous ,talented, innovative,and influential left handed guitarist.
Otis Rush is the most covertly influential left handed guitarist. Albert King would have to make the list too.