bishopF wrote an answer about Backcountry.com Shift Welder Hoody - Men's on August 24, 2009
Depends on the type of fit you're looking for. I'm 5' 10" 175# and I wear a Large. The sleeves run an 2.5" past my wrists and the length is 5" past my hips, even a little more in the back with the drop tail. There is room for a base and mid layer underneath.. I tried a Medium but it only had room for a baselayer under it. The sleeve and hem length was more to my liking but it was too snug on my hips so I went with the large.