let me start by saying that these shirts are snug.  Not tight.  Snug.  I wanted to get small, but opted for medium instead.  That was a great call.  I would recommend one size larger than you think you need.  Other than that, this shirt is incredibly soft, incredibly confortable, the color (sapphire for mine) is vibrant and nice.  At $21 (my price) these are a steal.  I will defenitely get more, especially if I can find more colors, other than black and white.  if these sounds appealing to you, I recommend you give it a try!