Smartwool Men's NTS Midweight Crew

Smartwool midweight
For colder weather this is a wonderful underlayer. I just wear this with my Arcteryx insulated jacket and it is plenty warm to keep me toasty in 10F that we had in the past week. This midweight is warmer than the micro weight smartwool but wearing indoor is just as comfy and not overly warm.

Great Sweater
SmartWool does it again. The fit and quality are both great. It's soft and warm without being too thick or too hot. While I haven't replaced all of my fleece with wool, I'm headed in that direction because wool smells better longer, wicks moisture better, and keeps it classy.

best baselayer for cold weather
This was my first merino wool purchase (prior to that it was patagonia fleece or capilene). This was the smartest purchase I made for the winter months. As a baselayer, it takes the place of 3 cotton layers. I wear it next to skin and do not experience any itching at all. I have capilene 3 shirts from Patagonia and as much as I like them, the smartwool NTS midweight is by far superior in cold weather. As far as care - I wash it in cold water and dry it on low - no issues with pilling or shrinkage. I'm 5'9 145lbs and fit into a size M for this shirt. The only negative is that it's pricey however if you can get it on sale or with a discount coupon, it's worth it -- i own 5 of them.