For me, the top three (none of which are particularly folk, but they're all singable) were Reba McIntyre's "Take It Back," Linda Ronstadt's "You're No Good" and the Waitresses "No Guilt." Best folk -- The Water is Wide or Tiny Sparrow:

Come all ye fair and tender ladies
Take warning how you court your man
They're like the stars on a summer's morning
First they'll appear, and then they're gone

I wish I were a tiny sparrow
That I had wings, and I could fly
I'd fly away to my own true lover
And all he asked, I would deny

If I had known before I courted
What all his lying would have done
I'd have locked my heart in a box of golden
And never would have courted more...