The OG, Amundsen is definitely one of the most popular along with 66 North from Iceland. With Icelandair's direct flight from Denver to Keflavik many Coloradans have visited the land of Fire and Ice. While there, 66 is prominently displayed. In fact, when you change planes at the airport you basically walk through a 66 North shop. Yet, once you return to the United States, 66 North is nowhere to be found. In fact, Aktiv is the only retailer in the US to carry it. Another popular brand is Ivanhoe from Sweden which is focused on wool in all its wonderful forms.