Rowan Big Wool is a super bulky yarn that's happy anywhere between 8 and 10 stitches to 4 inches, Big Wool is my go-to for immediate gratification projects.  On a US 15, sweaters knit up in a week or two.  Soft and smooth with a lovely twist, Big Wool has great stitch definition and is soft enough for next to skin wear.  There are tons of sweater designs for Big Wool that are actually flattering, which is hard for a super chunky yarn. I especially like the designs feathers in the Big Wool Collection by Quail Studio.