Burton Approach Under Mitt
These were the first mittens I ever tried. Gloves could never keep my hands warm enough and these definitely did a lot better job. I like the removable liner because you can get into your pockets or whatever without your hands completely freezing. Only downside, they barely made it through my season (70-80 days though). The right palm got worked from strapping in and out of my bindings so much.
My hand measures between 2.5" and 3" at the knuckle. Went with the medium because of that. Fits great