Reading through this thread has made me realize how horribly sheltered I have been when it comes to yarn. Possum?!!!
I haven't been doing this long enough to have a favorite, but I was at Michael's today and even though I swore I'd only buy one skein of Caron's Simply Soft because it was on sale, I saw this gorgeous color yarn and couldn't resist and bought the last two skeins - the Red Heart soft yarn in the color Embers. I have no idea what I'll knit with it but I couldn't resist it, such a beautiful color.