Patagonia Capaline. i have tried almost everything on the market and Patagonia is by far the best at wicking and maintains low oder retention. My first pair was purcased in 1996 when i went to Bosnia following the signing of the Dayton Peace Accord. i spent 90 days in country with one pair of medium weight capaline.
I used the same original pair and a second set in Montana working as a whitetail guide with an outfitter in the eastern part of the state in 1997. That totalled 60 days, my first 30 days i spent scouting and getting to know the land. the following 30 days involved an unbelieveable amount of time, like 18 hours a days, outside in the weather. Both trips i had access to washing machines but only washed every 4 days, give or take a day, sometimes as a test, and sometimes cause i was not able to get to my residence.
I am also a fanatical waterfowl hunter, spending many hours a day in waders either sweeting or freezing my behind off.
I do a little rock climbing, ok, at one time of my life a lot, i mountain bike, hike and backpack, love to do long backcountry style hunts, snowski, snowshoe, and winter camping. i still own that first pair of capaline.
So, just to let ya know i have used polypropalene (dont waste your money, it holds oder from day one and will get real itchy if you by accident put it in the dryer, trust me on this one)
i have thermax, duofold, marmot, northface, helly hansen, cabelas brand, REI brand, smartwool, Under Armor and am currently testing some of the new stuff with X-tatic.
OK, so just to set another part of this story right, i wear Under Armor tec t's everyday at work, 5 days a week. i think i own about 14 shirts from under armor and like it a lot. i have been doing this for the past 29 months. i have not tried their cold gear yet !
to further my lifes goal at trying to be comfortable in the outdoors i have found that i prefer the mid-weight pair as a first layer, after that many times i will wear heavy weight in combination with the mid-weight and then my Sleeping Indian wool as a top layer, or goretex when i am climbing, duck hunting, etc.
I will have to admidt that over half of my longjohns were paid for by work and one set was a gift.
So, basically if i were to spend my hard earned money on longjohns my vote would go to Patagonia Capaline.