Cobain and Morrison and Hendrix each gave expression to a large part of a generation, in Cobain's case to the extent that "Teen Spirit" dominated the form of that type of music for a good number of years.

Joplin's ferocity and power struck me as of greater musical impact.

Brian Jones? Not in the league (although better than the Stones guitarists after him). A look at his track credits shows nothing very remarkable.

Having listened to the Winehouse clip, it bored me. That sort of cafe jazz does. I would go along with "derivative". Having read some of the comments, that anyone could find Winehouse "better" than Etta James simply astounds me. Not that I think Winehouse was bad (although I did find her derivative or as is said above, tending to pastiche). I just don't see her as a musical genius to the standards of (say) Stevie Wonder, Sly Stone, Prince, Michael Jackson, Diana Ross, Howlin Wolf, Grace Slick, BB King, Alvin Lee, Bob Marley or Martin Carthy - or even a singer to the quality of June Tabor, Mahalia Jackson or Mavis Staples in her heyday.

She was a perfectly adequate musician who failed to excite me, and it's a shame she was so screwed up, and probably a bigger shame what she put her parents through one way an another.