Under My Skin. It has the least fillers and some of her best songs. It may not have the most listens on any individual song for me but as a whole it is her best quality work. Let Go is a bit childish compared to UMS and TBDT is very childish. I love GL and it has few fillers for me but songs feel old half way through the songs to me.

UMS.

Under My Skin simply because of Take Me Away, Together, AND THE FLAWLESS Fall To Pieces.

The Best Damn Thing > Let Go = Under My Skin > Goodbye Lullaby

Let Go