Hands down, no doubt about it, The Cleansing is my favorite scene in Winter's Heart. I've researched that chapter (Chapter 35: With the Choedan Kal) so much, quoted it so often in discussions on the Dragonmount Yahoo Group, that it's easily one of the scenes I know the best and is indeed, one of my very favorite scenes in the entire series.
It's fantastic in the audio version too, of course. ;o)