I would imagine most are too young to appreciate Jimi Hendrix and his stuff wasn't highly commercialized.
I see Randy Rhoads on that link Amanda posted and I used to literally "girl crush worship" him in my teens. *sigh* But alas, his life was not long here on earth to truly see how his career would have prospered further with Ozzy or others.
So to answer the question, I'd have to go with Eddie Van Halen. Van Halen was hot in the 80's and his name is well recognized commercially. Mostly anyone could sing along to a Van Halen song, even St. Peter! I don't think he's "as talented" though as others, just going with the commercial answer.