Whether it be made from loose fibers, knit, crochet, or commercially made, I adore felt. Creating a fabric by wadding up a bunch of fibers seems like magic. I have created a few knit and hand felted items, like this, and this, in addition to a few scarves, but would like to explore the medium more. Here is a list of a number of felt artists that I find truly inspirational.
Gail Crossman Moore
Ann Kyyro Quinn
Nicole Chazaud Telaar
The International Felt makers Guild has some good resources too. What felt artists do you like? The rose in the photo was created from a Two Old Bags pattern.