Uggs vs Emus vs Bearpaw?

So I've been relying on my Airwalk "ugg" style boots this winter and though they are going to last me JUST until spring is over, I'm thinking of investing in the real thing for next year. I want to be sure that whichever brand I purchase from is the most durable and the warmest (I live in Ontario, will be moving further north for school). So out of the three brands -- Uggs, Emus, or Bearpaw -- which are the warmest and most durable? thanks :)