No other guitarist had as much impact on heavy metal guitar as Randy Rhoads. Jimi Hendrix laid the foundation, for sure, and Eddie Van Halen was doing very similar things, but Rhodes did something that neither of them did. He died very early in his career. Earlier than Hendrix -- with only 3 active studio recording years.
If Hendrix is a rock and roll legend, Rhoads is a martyr. His neo-classic style influenced nearly every serious heavy metal band around him -- those that were already putting albums out and those that were just forming.
But don't take my word for it:
I was having problems with the video synch on these videos, but they're very worthwhile -- live performances of Mr. Crowley and Crazy Train.