Under I'd say Malcom Young, Hillel Slovak (listen to early rhcp if you don't already know any he was really talented), Ritchie Blackmore, and Billy Corgan, listen the Geek USA solo.

Overrated, these could be controversial so don't kill me, Eric Clapton, and Kurt Cobain, Don't get me wrong I love nirvana but Kurt was not a humongously talented guitarist, he was very creative and a master of less-is-more, but he wasn't that Great, as for Clapton it's already been said