I don't listen to much Non-English speakers most of the time (I'm most well versed in Reggaetone/Latin pop/folk artists in that regard and they're mostly guys [the ones I've come across]), but I'd throw Brigitte Fontaine a shout. Went through an
~zomg avant garde muziak is soooo kewl~ phase last year (where I also got into Diamanda that I
mentioned earlier 
) and the power of
Comme a la radio alone (cause I haven't listened to her other stuff yet) >>>
Shakira also but she crossed over, so.
I've heard of Mrs. Hardy but haven't listened to her.