Dress shirts are impossible. I can't find any at all, over-the-counter, which fit. I'm not that big (among most on this forum), but my arms require an XL, and I have a 30" waist. So it's baggy, saggy torso or my arms turn blue from cut-off circulation in the biceps. I work really hard to be this way, so I don't mind showing off a little with tighter sleeves. But I also don't want to be uncomfortable. For tanks and muscle shirts, regular mens Medium is fine. Luckily, I can wear those 80% of the time, weather permitting.
Charles