I've always had good luck with Rocky's brand boots from Cabelas(available other stores too). The Thinsualate insulation and (1) pair of Merino wool socks makes for an awesome winter boot combo. Many people make the mistake of throwing on mutiple pairs of socks thus restricting the blood flow to the feet and toes and also causing the feet to sweat. The Thinsualate insulation comes in gram weights(example 400 gram thinsulate) which is a measure of the weight of insualtion. If you are going to be active with the boots(walking, hiking) you want a lower number. For still hunting(deer stand, sitting) you want a higher number.