When I buy round neck T shirts from shops, for example from Uniqlo, if I choose M size it would be too fitting and it looks like as though I'm showing off my muscles (I go to gym quite often), and it doesn't feel very comfortable because too tight.

If I buy L-size shirts, they would either be: i) too long (made for tall men. I am only 5'7. The worst I've seen is Under Armor's sports shirts. Damn long, the bottom of the T-shirt can reach my crotch area), ii) the sleeves would be too loose around my arms, like this.

Where to find nice T shirts that fits well on the body and emphasizes the shoulders and chest and the sleeves aren't too loose around the arms? Or do I need to tailor them? But do u ever tailor T-shirts? I've never