While I prefer Sitka Gear (Celsius for cold weather), I will say here that I would wear the Cabela's Berber if I didn't. It's their outfitter camo in a woolly-looking material. Very quiet (SILENT), very warm, a touch bulky, but I really like it. I've worn it under the outer Sitka layers on super cold days (the Sitka compresses nicely), although now Sitka has some great insulative layers available too (Kelvin series).
If you've got some Cabela's money to spend and are not going to go Sitka, I'd recommend their Berber series. Nice subdued camo pattern too.