1) What yarn (that you don’t have/haven’t used) would make your stash “complete”?
2) What yarn do you never want to be without?**
I think I definitely need some basic Cascade 220 to make my stash more complete. I don't have any at the moment but would love to get some and keep it in my stash at all times. It makes for great felting. And also Noro yarns make a great stash staple in my mind. I just cast on with my last skein of Noro so it's going to be time to do some stashing soon. (right after that lottery win)
I never again want to be without lace yarn or sock yarn.