Aw, I was just yanking your chain about my man Angus. The list is actually fulfilling as long as I think of 'rock' guitar players.
One I really don't agree with is Prince. Songwriter? Musician? Producer? He's your guy. Guitar player? I don't hear the guitar influence he's left behind and I wouldn't say he was on top of the heap of guitarists at any time in his career.
The only other one I would add is Tom Morello who I feel kept Rage from sinking into the myriad of muddled and generic rap/rock bands and helped them stand out. I would sacrifice J. Garcia for him. But that just me.
Other than that, I can probably name at least one riff from the others that will probably stand the test of time and that's a good thing since the music that is remembered will be the influence later on.
Makes me think though, I'd really like to see someone do a fantasy game with music. You could base stats off album sales, concert gross, top ten hits, etc. Of course, then everyone would be posting "Have you done your fantasy singer rankings yet?"
Sorry, didn't mean to hijack.