I've felted a lot, and this yarn has been the most reliable.
http://danceswithwool.wordpress.com/2008/01/24/knitting-tips-my-favorite... [1]
Anyone else have favorites?
Links:
[1] http://danceswithwool.wordpress.com/2008/01/24/knitting-tips-my-favorite-felting-yarn/
[2] http://crochetme.com/forum/yarn-organization-0
[3] http://crochetme.com/forum/angora-goats-and-mohair