Good old Icebreaker
It's been eight years since I brought back my first Icebreaker T-shirt from New Zealand ... and I've still got it and I still use it. The size has shrunk slightly with all the laundries but that is as advertised.
This new one has a slightly looser fit (which I don't like so much, actually, thus only 4 stars) but the lighter quality makes it suitable for warmer conditions (which I like). Comfy to wear and does not smell -- GREAT.