@matigo But even Uniqlo is baggy! (And their oxford shirts are rubbish — get rough after a few washes, unlike JCrew.)
Tshirts are so hard to get right that I've taken to wearing plain black short-sleeved undershirts because they're the only ones that don't drape like a nightshirt on me. And I only wear black tshirts so I'm not bothered by the lack of choice.