o o o o, memememememe! i have a good answer!~
i just knit my niece the one skein wonder and i used knitpicks superwash wool in ballerina. i love it! it is super soft. i can't believe wool is this soft! and it got even softer when i washed it in kookaburra wool wash before i blocked it. i was sort of 'programmed' to think wool was scratchy, based on my past experiences with store-bought sweaters. :( i posted pics of the shrug in my blog: http://dakatzmeow.wordpress.com/
if you want cotton, hurry to knitpicks (try to use a link here so kp gets credit). they have crayon on clearance. it is 100% pima cotton and oooooooooooooooooooooh so very soft. i'm loving it. it's $1.99 a ball!
i just got my shipment of crayon: buttermilk (for the plain vanilla pullover pattern), periwinkle and light blue.
sorry to gush, but i'm loving this stuff!