Super warm mitts
I was never a mitten fan, as I didn't like the lack of dexterity that accompanied them. But for my trip to the Arctic I thought they would be the warmest option. After asking around, I went with these, and was very glad I did! I must have abnormally large thumbs, because I had to get the large in order to fit them, but that left some extra room for my fingertips. Even so, they were warmer than they've ever been with gloves, even at -40. And that was just standing around. If I was moving (such as the many times we had to dig cars out of snowbanks), they were almost too warm! I didn't even use the nifty pocket for the handwarmer packs, but they're there if you want them. Expensive? Yes, but worth every penny when it comes to comfort in extreme cold.