Shakira? Genius? Really?
When we're talking about those who are worthy to join the pantheon of musical geniuses like Hendrix, we should be speaking in terms of people who have mastered their instrument and who have the natural ability to express themselves in creatively new and brilliant ways.
I don't understand Shakira's Spanish albums, but if her English work is any indication, she is an incredibly talented artist... but I wouldn't say genius.
As for Winehouse, I would confidently assert that her music is genius (however sordid and misguided her personal life may be). A closer comparison for Winehouse than Hendrix may be Janis Joplin whose life was also pretty controversial (even when drugged out rockers were the norm). Beyond addictions, they share a talent for using words and melodies to resist the status quo and to carve out a space for widely unpopular ideas and perspectives. Even worn out premises like breakups and falling in love take on new life, new expressions and new paradigms through her songs. And if you double check the charts or listen to her albums you'll find no trace of a one hit wonder.
jsttennis77, I've seen some of her horrible live performances, but if you hunt down the ones where she's not completely cracked out you may find the live tracks are some of her best. Here's one where she's only mildly tweaking