Another merino vote. Just recently bought my first wool base layers and socks and have so far been very impressed with the smell factor as well as the moisture wicking abilities. Could definitely use some more!
I voted synthetic as that is what I mostly use. The only merino I have is in socks. My favorite shirt is the wasatch crew top. I on't like to wear a lot of clothing even in cold weather. The wasatch top, a puffy, and the hard scrabble jacket keeps me good for most situation.