I love mohair yarn. Love love love.
Whenever I hit a LYS, I always check the odd-balls basket for skeins of mohair. I don't care about color, weight, or anything--I just buy it. It is the ultimate stash yarn because it's so versatile.
Here's what I've made with mohair over the last few months. Oh crap, I think I mean "over the last year," not months, at this point. Whatever:
From left to right [links are to my Ravelry project pages]:
Wisp [modified with Victorian lace trim].
Oread [a version of the Pi Shawl -- instructions here].
And that's just the shawls.
What's your favorite yarn/fiber type? (Don't say Cascade 220. Snore.)