Blizzard and Polar fleece are both great in that they go on sale a lot too, so you can buy them for 40-50% off at Jo-Ann. You save a lot buying them then!
Yah, I lucked out when I first built my first one that the Blizzrd Fleece was on 50% off, so I ended up buying quite a bit of it then. I still have enough of one of the colors to make two or three more Glorified Sock puppets.
The next time it goes on sale, I'm going to buy a ton of it in several different colors.