+1 on Danner. I had some insulated combat-boot Danners issued to me in the Corps (probably the same ones Bailey mentioned above), and they held up well and were comfortable throughout a lot of ground-pounding. I just bought a pair of Danner Big Horn gtx with 400g Thinsulate for this hunting season and they were worth every penny. I like a boot with an aggressive sole, tall enough not to rub on my ankle bones, the more leather the better, and some insulation. Can't go wrong with Danner.

I also still have a pair of Bates combat boots that I bought to wear in garrison because they were good leather and easy to shine. I wear them out to the range still, but they aren't nearly as comfortable as my Danners.