I have only purchased Lion Brand Homespun on a regular basis for my afghans and such. I do have some Red Heart I purchased for an afghan for my sister because teh colors were so pretty, but afterwards I realized just how rough and unmanageable it is. So sad because years ago that is all I purchased for my projects.
I have not used Vanna's yarn yet, but I do like the feel of it and you can catch it on sale at JA's or HL's.
Some of the fufu yarns are fun but so expensive.
If I learn to knit, I will be using Alpaca yarn for socks and mittens as it is so warm, hypo-allergenic, and wicks away the moisture.
The quality of everything is going down hill because of wanting lower prices, quantity, and availability. We will reap what we have sown before we know it.