Perfect fit, color, style, construction and fabric.  I am 5'7", 160lbs, 34DD and the XL is a perfect fit.  If you want a more fitted look and about my size, the L would work.  But if it shrinks any, you might want to go with the XL.  I haven't washed mine yet.  The quality of this shirt looks like it came from a nice boutique.  Great buy.