I'm not picky about my A-shirts but the one thing I need them to be is long enough to stay tucked in all day. I only wear them as undershirts to my dress shirts and they are long enough to not ride up past my pants at any point during the day. That is why I love these shirts. I'm 6'2" 185lbs and got the medium, which makes it slightly on the snug side but I'm good with it.

*Update* Be sure to air dry them instead of the dryer. They will shrink.