Carhartt C61
If it's a particularly cold day (more than 20 below) I'll layer a fleece under it.
You should check up active GearUp, they have crazy good deals on quality stuff...which is why I have a shit load of smartwool stuff and 4 different pairs of inov8susually 20 to 30 degrees. I run hot so armpit vents are clutch. I don't really want a detachable inner liner because I always have problems with zippers and shit breaking.
Thanks pals I love all of you
Anyone wear Uniqlo heat.tech stuff? I like the slim profile