I rarely wear t-shirts, unless they are sports/university logo short-sleeves.
Generally I wear long sleeve button ups. Half of them I can get away with at work without looking too sterile or too under dressed. The others I wear for informal settings, but still look dressed up. Most of the clothes I like are structured, and I forgo the shirts that art too shiny/blingy and go for the more matte/subtle styles. Generally, I avoid bright colors so it's like a subtle kind of flashy.
With age I have shifted from wearing mostly plaids and flannels to somewhat solid color shirts. Though, I still wear some plaid.
So, these are a few examples that are pretty close to my style. I usually get one or two of these shirts every three months since they are pricey...but I take care of them and would rather have fewer nice clothes that a bunch of clothes I'll never wear or are made cheaply (don't last long). Not to push brands, but these are sold at Buckle stores, my favorite brands being Affliction and Roar.