It's really hard for me to find shirts that fit. I have a small upper body for my height (5"5'). With narrow shoulders and a long torso, petite shirts are usually too short and regular shirts tend to be big. Before H&M came around, I used to pay $80 for a Banana Republic shirt, but then it usually is a little too tight around the chest. H&M amazingly fits really well - and the price is great for decent quality material.
I bought a few H&M short-sleeved button down shirts a few years ago, and they ended up being pretty nice shirts for the price. The fabric is pretty thin, but the construction of the shirt seems solid, and H&M usually keeps up with what's currently in style.