the mukluk: "a soft boot worn by eskimos, often lined with fur" (thank you dictionary.com!)
..in today's jargon: the classic ugg.
personally, i am not a fan of these boots, but i understand the practicality. it's a simple boot that keeps your feet fairly warm (unless it's wet outside and you feet thus get wet and begin to freeze) and can go with a multitude of outfits.
the bad side of the ugg (other than that freezing wet feeling i described earlier) is the slippery sole. if you are wearing these things anywhere there is actually snow and ice you are out of (muk)luk.
the patagonia women's lugano waterproof boot:
the north face w abby ii:
if you love ugg, they have a couple good selections with cute style, thick treads, and waterproof material. like the surfcat boot: