I was thinking about this while knitting my first blanket square in rowan today. That's scrummy to knit with as is debbie bliss cashmerino. Both very forgiving and very soft. My all time favourite though is rowan all seasons cotton-Aran weight, feels lovely and soft and washes brilliantly. Not ventured into any more unusual yarns and most of my knitting is less classy than rowan and Debbie bliss!